Gemstone Facts & Information

Stones are listed in alphabetical order. Links to information
about American turquoise mines can
be found under the turquoise heading on this page. We will continue
to add more samples of gemstones in the future.
AGATE & Agate Gemstones
Agate is a member of the Chalcedony species. It's distinctive
concentric, banded, shell-like appearance is sometimes enhanced by
dying the stone. The bands within this stone are usually multicolored,
consisting of fine quartz fibers. Some deposits have a variety of
strong to soft color variations like those that had been found in
Germany, while others, like the Brazilian Agate, have naturally dull
gray bands for which dying will create a more dramatic effect. Since
the dye will be absorbed with different intensity, depending on the
composition of the bands, it is very difficult to tell the difference
between it and naturally colored agate, unless the color used rarely
appears normally in nature. This gemstone has been used in all types
of jewelry from Victorian jewelry to Southwest Jewelry.
Agate is found as a ball or oblong nodule that can range in size
from a fraction of an inch to several yards in circumference. Initial
important deposit finds in Germany have been pretty much worked out,
but reserves remain in Brazil and northern Uruguay. Other deposits
also exist in Australia, China, India, Mexico, Madagascar, Nambia
and the states of Idaho, Oregon, Utah, Washington, Wyoming and Montana
in the United States.
AMAZONITE & Amazonite Gemstones
This green sodium feldspar has derived it's name from one of it's
origins. Or perhaps it's green color conjured up images of the lush
green forests of the Amazon, but there are deposits taken from Brazil.
This stone can be found in China, India, Kenya, Madagascar, Namibia,
Russia and the state of Colorado and Nevada in the United States.
In recent years the gemstone Amazonite has been used in all kinds
of jewelry from Victorian Jewelry to Southwest Jewelry.
Amazonite is generally opaque and can be sensitive to pressure.
This gemstone is sometimes confused for Chrysoprase, Jade or Serpentine.
AMBER, A FOSSILIZED TREE RESIN
PHYSICAL CHARACTERISTICS:
Color is amber yellow to orange.
Luster is resinous.
Transparency: Transparent to translucent gemstone.
Crystal System does not apply because amber is amorphous (meaning
it does not have an ordered structure).
Habits include nodules embedded in shales or sandstones and those
that are washed up on beaches.
Fracture is conchoidal.
Hardness is 2+.
Specific Gravity is approximately 1.1 (extremely light and can float
in salty water).
Streak is white.
Other Characteristics: Can be burned, fluorescent under UV light and
is much tougher (will not crumble as easily) than modern tree resins.
Notable Occurrences of this gemstone include all Baltic countries;
Venezuela; Russia; Romania; Burma; in coal seams in Wyoming, USA and
the Dominican Republic.
Best Field Indicators are color, density, toughness, softness and
trapped insects.
THE SWEDISH AMBER MUSEUM
The Swedish Amber Museum in Kämpinge is close to sandy beaches
in the southwestern corner of sweden. When the storms begin in the
autumn, the local people head for the beach to search for the "Gold
of the North". Maps at the museum give a hint about good locations.
Anyone can find a pebble, but the 1 kilo pieces and bigger are very
rare. Amber from coastal erosion is transported along the shores of
all the countries around the southern Baltic Sea. Its weight is slightly
heavier than the water in the Baltic Sea. It floats like a soap on
the bottom, following the streams until it comes up on the shore or
sinks in shallow water. Sometimes it is mined in clay deposits or
found among the quartz sand. In saturated salt water it floats. (Melt
a couple of spoons of salt in a cup of water and test your amber.)
HISTORY AND TRADE of The Amber Gemstone
The museum shows artifacts from the Stone Age through the Viking Age,
to the jewelry of today, from Victorian Jewelry to Southwest Jewelry.
During the Middle Ages, prayer beads were exported as the main
product of tooled Baltic amber. From the 16th century into the 18th
century, bracelets, necklaces, containers, boxes, bowls, plates, flutes,
buttons, mouth pieces for pipes, chess sets, watch cases and even
luxury interior fittings were made using amber. The bulk of the amber
trade took place in Königsberg and Danzig, modern Russia and
Poland, respectively.
In Rome, during the reign of Nero, Romans travelled to the coast
of germania to purchase amber. One expedition proved so successful
that a special "amber day" was arranged, where this costly
item was used to decorate the gladiator games. In the protective netting
between spectators and the arena, a glittering amber ornament was
placed within each knot and the actual arena was apparently strewn
with amber! During that time, the southwest coast of the Baltic Sea
was the most important supplier. The Romans maintained regular trade
connections with northern Europe along the so called "Amber Routes".
Even earlier, amber was revered by the Phoenicians, who traveled
the seaway to what is today the Danish west-coast. Grave-finds from
all countries around the Baltic Sea prove that earlier amber was a
common trade object to Stone Age man. Since prehistoric times amber
has thus been a readily sought after material. Its color, luster,
warmth, aroma, electric properties and background, in a scientific
sense, place amber in a special category among ornamental stones.
AMBER AND MAGIC
In days gone by, amber was acclaimed to possess the power of healing.
Worn as a necklace or charm, or carried around in small bags, amber
was believed to be a remedy against such ailments as gout, rheumatism,
sore throats, toothache and stomach-ache. It was also believed that
amber accelerated birth and was a good remedy against snake bites.
To guard against the swapping of a new born baby, the infant it was
often given an amber necklace to wear. Amber was supposed to contain
magical powers, which is why heart shaped amber charms were carried
to offer protection against evil forces and help against witchcraft.
AMBER FACTS
During the Roman times, higher prices were paid for small gemstone
amulets in amber than for healthy slaves.
In 79 AD, Plinius wrote that the women of northern Italy wore
amber beads against thyroid.
Martin Luther carried a piece of amber in his pocket as a protection
against kidney stones.
In ancient China it was customary to burn amber during large festivities.
This practice both signified the wealth of the host as well as honoring
the guests.
According to Mohammed, a true believer's prayer beads should be
made of amber.
The father of healing, Hippocrates, declared amber active against
a number of diseases including delirium tremens.
Over 2500 years ago, Thales of Miletos discovered that when amber
was rubbed against cloth, sparks were produced and then the amber
attracted husks and small wooden splinters. This force was given the
name "electricity" after the Greek word electron which means
amber.
AUTHENTIC AND FALSE AMBER GEMSTONES
In the display the Amber Museum also explains about how to tell the
difference between true, treated and false amber. Amber is often sold
heated, melted and pressed or even mixed with or made from synthetic
materials.
Most true Baltic amber is milky and pale under the crust. The
warm "amber" color occurs first after it has been exposed
to oxygen for about a hundred years. To make amber more attractive
to the purchases, todays industrial amber jewelry producers are manipulating
to get the warm brown-reddish amber color, which often also includes
discs, called sunspangles.
The most common method make amber clear is to put the material
under pressure and heat in an autoclave together with nitrogen. After
this procedure, it is put into an oven to obtain the sunspangles and
the cognac color. This heating and treating is made to make amber
jewelry more attractive.
Baltic amber occurs naturally in a variety of colors: white, yellow,
brown, black, red, green and blue. The most common are honey-colored
and milky. A small percentages is bone white, due to microscopic gas
bubbles. The clear and translucent amber results from flowing and
dripping resin. This kind often shows layers from continuing flow
on already dried resin. The black and dirty brown colors are caused
by a mix of resin, soil and plant fragments. The most rare have a
tone of green or blue caused by gas or inclusions. If the craftsman
keeps part of the natural shape, when sanding the raw amber, the crust
or inclusions give a natural variety of multicolored tones.
It is possible to melt amber pebbles and press them to bigger
lumps. It then becomes harder, and less brilliant when cut. Any color
can be added in this procedure. This pressed amber is still considered
as natural amber by some producers.
PLASTIC COPIES
Since the bakelite and plastic era began early this century, there
has been a number of fake amber qualities in the commercial market.
Bakelite necklaces were sold in Europe in the early twenties, when
amber was in fashion.
In the markets in Morocco, North and East Africa, as well as in
the Middle East and India, amber colored plastic necklaces are very
common. They are often sold as antique trade beads. Sometimes they
are old, very beautiful, large egg-yolk colored strands, but they
are still plastic, and tend to be heavier than amber.
The original, real trade beads, which were distributed from northern
Europe around 300 years ago, are very rare to find in the market.
It is difficult to see the difference, but if a heated needle is put
into the hole of a bead, the smell of burned plastic immediately appears.
Baltic amber smells like pine resin.
Even without heating the needle, you can tell the difference.
Plastic is elastic, and the needle gets stuck in the material, but
true amber is brittle and small pieces will chip off by the pressure.
A scientist from British Museum of Natural History, found a falsification
in their collection. A very well preserved fly was described as a
palaeontological rarity from the beginning of the 19th century. Someone
had divided the piece and carved a concave hole and then put the fly
in and covered it with an "amberlike" material before gluing
the halves together again.
Since the "Jurassic Park" movie, fortune hunters from
all over the world have tried to create attractive plastic-imitations
with inclusions, sold as true amber. Sometimes even mammalian hair
and feathers are skillfully baked in. They are often carved as a Buddha
or other figures, sometimes presented with lumps of the same plastic
material with a surface that looks like a natural amber crust. To
complete the imitation the faked raw lumps are dipped in oil with
a smell of resin.
COPAL, YOUNG RESIN
Resin has always oozed to protect trees all over the world, and the
process is still going on. The older the resin is, the harder. It
takes millions of years for the resin to harden to amber. When the
resin is younger than one million years, it is called copal, a product
traded as raw material for varnish and lacquer before the modem synthetic
products were developed.
In New Zealand, copal was mined and exported all over the world
in the beginning of the century. Today the industrial remains are
shown in museums on the North Island. Among the large pieces in the
showcases there are quite a few with perfect lizards and giant spiders
enclosed, the result of a kind of melting technique used by the miners.
There are almost no inclusions in the New Zealand "Kaurigum",
opposed to the very fossil-rich copal from East Africa and Colombia.
Copal turns sticky and smells like fresh resin if heated. It does
not take a good polish and the crust comes back in a few years. It
is transparent in a champagne color and very brittle. There are different
sources in many places, varying in age from a couple of thousand years
to one million years. Many people love stabilized Copal Amber gemstones.
IS AMBER FOREVER?
Unfortunately, amber is not forever. Roman beads, 2000 years old,
have developed a new thick crust. The Baltic amber gemstone jewelry
from the last centuries has the fine net of new crust on the surface.
It is possible to polish it, but it is very difficult with the faceted
gemstone jewelry that was common at that time.
Some amber from the Dominican Republic crusts already after 10-20
years. In Museum für Naturkunde in Stuttgart, germany, their
valuable collections of inclusions are preserved in plastic-coating
to keep them from the devastating oxygen. Only the amber deep down
in geological deposits has "survived" since it oozed from
the trees. So, what is found today is only very little of all the
resin the trees have produced during millions of years.
"JURASSIC PARK"
In the wake of the movie "Jurassic Park", the interest in
amber with inclusions has been increasing rapidly. In the movie, scientists
extracted DNA from dinosaur blood enclosed in the stomach of mosquitoes
in amber. Through cloning, real dinosaurs were created, and the rest
of the story you probably already know. Scientists from the British
Museum of Natural History, are now after years of testing, questioning
if earlier DNA extractions are conterminated. No successful experiments
proved so far.
Most amber found today was formed during the Tertiary Age, about
30-50 million years ago, after the dinosaurs were extinct. In a few
places such as Lebanon, New Jersey (USA) and Alava (Spain), amber
from the age of the dinosaurs (65-220 million years ago) has been
found, but in very small amounts.
REALISTIC SCIENCE
What the movie above all contributed to among scientists all over
the world was an increased awareness of how extremely well inclusions
in amber are preserved. After millions of years they are visible in
three dimensions, showing microscopic details clearly. They may even
show behavior or "stories" from the bottom of the prehistoric
forests.
The prehistoric conifers, (Pinus succinifera), from which Baltic
amber originates, were growing in a subtropical climate in what today
is northern Europe. Due to its light weight, Baltic amber was an easily
transportable material during the formation of bed deposits during
the iceages. Much of the amber found today has been relocated several
times. Different kinds of amber are found throughout the world. The
amber from Dominican Republic and Mexico comes from a leaf tree, which
grew in tropical climate.
USA EXHIBITIONS
After showing our collection of Baltic amber at the Tucson Mineral
show, the Amber Museum in Sweden has been invited to exhibit rare
specimens at natural history museums all over USA.
In our exhibitions there are many pieces including 40 million
year old "frozen stories". Some contain insects trapped
in the sticky resin during their mating act; others show behavior
like ants transporting eggs or carrying away trapped prey. Other specimens
include insects caught by spiders, sometimes wrapped up in webs, microscopic
arthropods on rotting leaves, fungus growing on dead substances, pollen
falling out of the anthers of a flower, small mites riding on beetles
and many more.
These frozen moments from the floors of the prehistoric forests
can teach us much about the fauna and flora at that time. Scientists
can compare inclusions in amber with todays similar species and study
the development through the ages.
The insects in amber are very much the same as the ones living
today. Their evolution began 350-400 million years ago. When trapped,
they were in the early Tertiary Age (30-50 million years ago), already
similar in appearance to today's insects. The mammals were beginning
to develop during this era, and a few inclusions of mammalian hair
are found, as well as some bird feathers and reptile skin pieces.
Recently an entrapped lizard in amber was found in Gdansk-area, Poland.
By
LEIF BROST
Swedish Amber Museum
AMETHYST & Amethyst Gemstones
Amethyst, is a transparent purple gemstone variety of quartz,
is one of the best known and most valuable forms of quartz. The name
“amethyst” comes from the Greek and means “not drunken”. It was once
thought to prevent the wearer from getting drunk and also thought
to bring peace of mind.
Amethyst is purple and ranges from light to dark which is caused
by iron or manganese compound impurities in the mineral. Amethyst
comes from many parts of the world and each locality can produce a
unique amethyst to that area or particular mine.
The following is a list of many of the more noteworthy localities
and some of the attributes that characterize the amethyst gemstone
found there.
Vera Cruz, Mexico -- very pale, clear, prismatic crystals that are
sometimes double terminated and have grown on a light colored host
rock. Crystals are typically phantomed, having a clear quartz interior
and an amethyst exterior. Some are sceptered and phantomed.
Guerrero, Mexico -- dark, deep purple, prismatic crystals that
radiate outward from a common attachment point. Often the crystals
are phantomed opposite of Vera Cruz amethyst having a purple interior
with a clear or white quartz exterior. These are some of the most
valuable amethysts in the world.
Minas Gerais and Rio Grande do Sul, Bahaia, Brazil -- crystals
form in druzy crusts that line the inside of sometimes large volcanic
rock pockets or "vugs". Some of the vugs form from trees
that were engulfed in a lava flow millions of years ago and have since
withered away. Other vugs are just gas bubbles in the lava. Some vugs
can be quite large. The crystals that form are usually light to medium
in color and only colored at the tops of the crystals. Most clusters
form with gray, white and blue agate and have a green exterior on
the vugs. Calcite sometimes is associated and inclusions of cacoxenite
are common.
Maraba, Brazil -- large crystals with unattractive surfaces that
are of a pale to medium color and often carved or cut into slices.
Thunder Bay, Canada -- a distinct red hematite inclusion just
below the surface of the crystals is unique to this locality. Clusters
are druzy crusts that line the fissures formed in ancient metamorphic
rocks.
Uruguay -- crystals are dark to medium and form in druzy crusts
that line the inside of volcanic vugs that have a gray or brown exterior.
The crystals are usually colored throughout, unlike the Brazilian
crystals, and form with a multicolored agate that often contains reds,
yellows and oranges. Often amethyst- coated stalactites and other
unusual formations occur inside these vugs.
Africa -- crystals are usually large but not attractive. However,
the interior color and clarity are excellent and polished slices and
carvings as well as many gemstones are prized and admired.
Maine, USA -- Dark druzy clusters that are not widely distributed
today.
North Carolina, USA -- Druzy clusters that have a bluish-violet
tint.
Pennsylvania, USA -- druzy clusters that filled fractures in metamorphic
rocks. They are generally a brownish purple and patchy in color.
Colorado, USA -- druzy clusters form crusts inside of fissures
in sandstone, often on top of a crust of green fluorite. Crystals
are dark but rather small.
Italy -- both Vera Cruz like crystals, although not as well defined,
and large parallel growth clusters with good evenly distributed color.
Germany -- associated with colorful agates that form a druzy light-colored
crust.
Ural Mountains, Russia -- a very clear and dark variety that is cut
for fine expensive gemstones, natural uncut clusters are rarely on
the market.
Variety of: Quartz , SiO2 .
Uses: Gemstones and ornamental stones.
Birthstone for: February
Color: various shades of purple.
Index of refraction: 1.544-1.553
Birefringence: 0.009
Hardness: 7
Cleavage: none
Crystal system: trigonal
Pleochroic: no
AMMONITE & Ammonite Gemstones
Ammonites are the fossilized, hard shells of extinct mollusks
that existed from the Paleozoic to the end of the Cretaceous era.
They were abundant in all the oceans. Their closest relative is the
chambered Nautilus from the Pacific and Indian oceans. After millions
of years the original shell is slowly replaced by minerals such as
agate or calcite. Ammonite fossils are found on every continent. They
are treasured for their appearance and form. Some show very intricate
suture patterns, which are created by the complex walls dividing the
inside of the shell.
The Navajos and other Native American Indian tribes carried ammonites
in their medicine bags for health and good hunting. They were called
Buffalo stones because of their resemblance to the North American
Bison. In recent year Ammonites have been used as gemstones in all
styles of jewelry from Victorian jewelry to southwest jewelry.
ANYOLITE & Anyolite Gemstones
Anyolite is a member of the Zoisite species. Usually opaque rubies
occurring within green zoisite rock with black hornblende inclusions.
It's colorful variations make it a beautiful specimen. The first known
discovery was in Tanzania in 1954. In recent years this gemstone has
been used in all types of jewelry from southwest jewelry to victorian
jewelry.
ALEXANDRITE &
Alexandrite Gemstones
Alexandrite is a variety of the Chrysoberyl species. It's name
is derived from the Russian Czar, Alexander the 2nd who was in power
when it was discovered in the 1830s. It's color changing properties,
dependant on the light source, are what makes this gemstone unique,
and sought after. Larger specimens show their color changing properties
best and can be very expensive. Sunlight changes it's hue to green,
while showing influences of light red under artificial incandescent
light sources.
Although originally discovered in the Urals, that supply has been
essentially depleted. Currently mined from Zimbabwe, Sri Lanka and
most recently from Brazil. Smaller deposits have also been found in
Tanzania, Burma and Madagascar.
Primarily fashioned into faceted gemstones, Alexandrite can be
quite expensive. Chemically identical lab created gems are available,
having the same color changing properties for considerably less cost.
This should not be confused with an artificial gemstone called "Zandrite"
which boasts complete color changing properties, but is essentially
a specially treated glass. This maybe one of the most expensive and
rare gemstones on the market, not much compares to this outrageous
gemstone.
APATITE & Apatite Gemstones
Found in many colors, but green is most common. Can be sensitive
to acids. Transparent to somewhat opaque, it has a vitreous luster.
Chemistry: Ca5(PO4)3(OH,F,Cl), Calcium (Fluoro, Chloro, Hydroxyl)
Phosphate
Class: Phosphates
Group: Apatite
Uses: as a source of phosphorous to be used in fertilizer, rarely
as a gemstone and as a mineral specimen.
Specimens
Apatite is actually three different minerals depending on the predominance
of either fluorine, chlorine or the hydroxyl group. These ions can
freely substitute in the crystal lattice and all three are usually
present in every specimen although some specimens have been close
to 100% in one or the other. The rather non-inventive names of these
minerals are Fluorapatite, Chlorapatite and Hydroxylapatite. The three
are usually considered together due to the difficulty in distinguishing
them in hand samples using ordinary methods.
An irony of the name apatite is that apatite is the mineral that makes
up the teeth in all vertebrate animals as well as their bones. Get
it? Apatite - teeth! Anyway, the name apatite comes from a Greek word
meaning to decieve in allusion to its similarity to other more valuable
minerals such as olivine, peridot and beryl.
Apatite is widely distributed in all rock types; igneous, sedimentary
and metamorphic, but is usually just small disseminated grains or
cryptocrystalline fragments. Large well formed crystals though can
be found in certain contact metamorphic rocks. Very gemmy crystals
of apatite can be cut as gems but the softness of apatite prevents
wide distribution or acceptance of apatite as a gemstone.
PHYSICAL CHARACTERISTICS:
Color is typically green but also yellow, blue, reddish brown and
purple.
Luster is vitreous to greasy and gumdrop.
Transparency: Crystals are transparent to translucent.
Crystal System is hexagonal; 6/m
Crystal Habits include the typical hexagonal prism with the hexagonal
pyramid or a pinacoid or both as a termination. Also accicular, granular,
reniform and massive. A cryptocrystalline variety is called collophane
and can make up a rock type called phosphorite and also can replace
fossil fragments.
Cleavage is indistinct in one basal direction.
Fracture is conchoidal.
Hardness is 5.
Specific Gravity is approximately 3.1 - 3.2 (average for translucent
minerals)
Streak is white.
Associated Minerals are hornblende, micas, nepheline and calcite.
Other Characteristics: An unusual "partially dissolved"
look similar to the look of previously sucked on hard candy.
Notable Occurrences include Durango, Mexico; Bancroft, Ontario; Germany
Brazil, Burma, India, Madagascar, Kenya, Mexico, Norway, South Africa,
Norway, The United States and Russia.
Best Field Indicators are crystal habit, color, hardness and look.
AQUAMARINE - Colorado's State Stone
It's name means "water of the sea" in Latin because
it's color so resembles that of ocean water. Iron creates this color
naturally in this stone, but heating specimens with lower iron content
will bring out the desired color permanently. When overheated though,
it can lead to discoloration. Attempts to improve color with gamma
and neutron irradiation can be done, but the changes aren't permanent.
Aquamarine can make beautiful faceted gemstones, but jewelers must
be very careful when using it for their creations because it can be
brittle. It is also sensitive to pressure. Aquamarine is Colorado's
state stone. It is the birthstone for March. In recent years this
gemstone has been used in all types of jewelry from southwest jewelry
to victorian jewelry.
AVENTURINE QUARTZ
Found primarily in dark green with occasional glittery metallic
inclusions of green mica or gold-brown to red caused by hematite particles.
Sources are India, Austria, Brazil, Russia and Tanzania. Used
by making into cabochons and carved figurines for jewelry and ornamental
items.
In recent years this gemstone has been used in all types of jewelry
from southwest jewelry to victorian jewelry.
AVENTURINE FELDSPAR - "Sunstone Gemstone"
Aventurine Feldspar (oligoclase), is opaque with glittery gold
or red inclusions. Rare occurrences of green or blue glitter are sometimes
found. The inclusions causing the sparkle are actually reflections
from minute goethite or hematite platelets.
There are deposits found in India, Madagascar, Norway, Canada, Russia
and the United States. Generally used by forming into cabochons or
other flat surfaces for jewelry, all kinds of jewelry from Victorian
Jewelry to Southwest Jewelry.
AZURITE & Azurite Gemstones
Chemistry: Cu3(CO3)2(OH)2, Copper Carbonate Hydroxide
Class: Carbonates
Uses: ornamental stone, pigment, minor ore of copper, and jewelry.
Specimens
Azurite is a very popular mineral because of its unparalleled color,
a deep blue called "azure", hence its name. Azure is derived
from the arabic word for blue. The color is due to the presence of
copper (a strong coloring agent), and the way the copper chemically
combines with the carbonate groups (CO3) and hydroxyls (OH). Azurite
has been used as a dye for paints and fabrics for eons. Unfortunately,
at times its color is too deep and larger crystals can appear black.
Small crystals and crusts show the lighter azure color well. Azurite
is often associated with its colorful close cousin, malachite
Green malachite is closely associated with azurite in many ways. Not
only do they frequently occur together (pictured above), they also
have very similar formulae. Malachite can also replace azurite, making
a pseudomorph, or an exact copy of an azurite crystal (only now instead
of being blue, it would be green). Compare their formulas:
Azurite's formula: Cu3(CO3)2(OH)2
Malachite's formula: Cu2(CO3)(OH)2
The charges on the copper ions are the same for both minerals
at positive two (each hydroxide has a charge of negative one and each
carbonate has a charge of negative two). But what causes the color
change from azurite to malachite if the charge on the copper remains
the same? Consider the formulas if they are rewritten as so:
Azurite's formula: Cu(OH)2-2(CuCO3)
Malachite's formula: Cu(OH)2-CuCO3
Notice the different amounts of CuCO3 in the two formulas. The
azurite seems to have an extra CuCO3, but the transformation could
be explained by an addition of an extra Cu(OH)2 to azurite's formula
to make two malachites as in the following equation:
Cu(OH)2-2(CuCO3) + Cu(OH)2 ----> 2{Cu(OH)2-CuCO3}
{AZURITE} 2{MALACHITE}
Since the Cu(OH)2 is more oxidized than the CuCO3, the malachite is
therefore more oxidized than azurite. This means that malachite represents
a later stage of oxidation and the increased oxidation is what causes
the color change. The actual formula for the conversion is a bit more
involved and includes the addition of a water molecule to two azurite
molecules and the release of a carbon dioxide molecule; leaving behind
three malachite molecules. The equation is represented as follows:
2{Cu(OH)2-2(CuCO3)} + H2O ---------> 3{Cu(OH)2-CuCO3} + CO2
2{AZURITE} {WATER} 3{MALACHITE} {CARBON DIOXIDE}
The oxidation is persistent and actually ongoing, although very slow.
Azurite paints made centuries ago have undergone the transformation
much to the imagined horror of artists whose paintings of beautiful
blue skies now have a most unusual green hue! Thankfully for mineralogists
and collectors, this transformation is one of the most asthetically
pleasing in the mineral kingdom. Although the malachite may soften
the sharpness of the azurite crystal, it generally leaves the specimen
intact and a whole range of transformations from pure azurite to pure
malachite can be obtained. There really is no comparison to any other
mineral to mineral transformation in terms of overall beauty.
Azurite is used in jewelry and for dyes as mentioned above. It
is also an unimportant ore of copper, although its significance has
been more impressive in the past. It is still considered a minor ore
of copper; mostly because it is found associated with other more valuable
copper ores. Fine crystal clusters, nodular specimens, and interesting
and beautiful combinations with malachite are important pieces in
anyone's mineral collection. The magnificent color of azurite is worth
mentioning again as it truly is a one-of-a-kind in the mineral world.
Azurite is one of those classic minerals. This stone has become popular
in all kinds of jewelry from Victorian jewelry to Southwest jewelry.
PHYSICAL CHARACTERISTICS:
Color is azure, deep blue or pale blue if found in small crystals
or crusts.
Luster is vitreous to dull depending on habit.
Transparency: Transparent if in thin crystals, otherwise translucent
to opaque.
Crystal System is monoclinic; 2/m.
Crystal Habits crystals are irregular blades with wedge shaped terminations.
Also, aggregate crusts and radiating, botryoidal, nodular and earthy
masses.
Cleavage is good in one direction and fair in another.
Fracture is conchoidal and brittle.
Hardness is 3.5-4.
Specific Gravity is 3.7+ (heavier than average).
Streak is blue.
Associated Minerals are numerous and include malachite limonite, calcite,
cerussite, quartz, chalcopyrite, native copper, cuprite, chrysocolla,
aurichalcite, shattuckite, liroconite, connellite and other oxidized
copper minerals.
Notable Occurrences include numerous localities worldwide, but special
localities produce some outstanding specimens especially from Lasal,
Utah; Bisbee, Arizona and New Mexico, USA; Mexico; Tsumeb, Nambia;
Shaba, Congo; Toussit, Morocco; Australia and in many locations in
Europe.
Best Field Indicators are color, softness, crystal habits and associations.
CARNELIAN & Carnelian Gemstones
A member of the Chalcedonly species, Carnelian is thought to have
been named after the color of the kornel cherry which it likens too.
Orange to brownish-red with varieties having some translucency to
opaque qualities. Iron contained within the stone gives it this coloring,
but heat can enhance it too. Color within this stone is generally
dispersed in cloudy patterns. This stone was very popular in Victorian
Jewelry.
Found in Brazil, Uruguay and India.
CHROME DIOPSIDE & Chrome Diopside Gemstones
It sounds more like an ingredient a chemist would use rather than
a jeweler, but this gemstone is a striking emerald green color. Can
react negatively to hydroflouric acid. Will actually melt under a
jeweler's torch. This stone is absolutely stunning in Gold Victorian
Jewelry styles.
Diopside is russian chrome diopside value a diopside chrome diopside
jewelry rough monoclinic chrome diopside diopside mines included pyroxene
mineral with composition star diopside MgCaSi2O6. It forms a solid
solution series with hedenbergite (FeCaSi2O6) and augite. Diopside
is found in mafic igneous rocks as well as in many metamorphic rocks.
It is also a constituent of the Earth's mantle.
Gemstone quality diopside is found diopside in two forms: diopside
stone the black chrome diopside wholesale what is black star diopside
star diopside and the chrome diopside (which includes chromium giving
chrome diopside russian diopside chrome diopside beads diopside in
greece it a green colour).
Most deposits are found primarily in Russia and Kenya.
CHAROLITE – CHAROITE GEMSTONES
Charoite is a relatively late comer to the marketplace, having
been known only since the mid 1970’s. The color of charoite is described
as a stunning lavender, lilac, violet or purple. The white chrystalline
“needles” give charoite a very distinctive appearance and depth often
forming a swirling pattern of interlocking crystals. Charoite is found
in the inerfluve of the Chara and Tokkin rivers, northwest of Aldan
on the Jakutsk area, northeast of Lake Baikal, Russia. This stone
as of late has become very popular in Southwest Jewelry, including
inlay.
CHRYSOPRASE & Chrystoprase Gemstones
Chrysoprase is a valuable variety of microcrystalline quartz (chalcedony).
Chemically it consists of almost nothing besides silicon dioxide.
The green color of Chrysoprase from Australia comes from the traces
of nickel within the gem stone. On the Mohs scale of hardness the
chrysoprase gemstone measures up at around 6-7.
The chrysoprase gemstone was used to make seals and signets by
the Greeks, Romans and Egyptians. During the same time jewellery was
also made from the gemstone. Chrysoprase containing jewelry pieces
are also recorded from the Victorian era.
As mentioned above, the nickel content in chrysoprase gems gives
the gemstone a green color. The green color of chrysoprase from Australia
can vary from, very pale green through apple green and into a deeper
rich green. The gemstone is generally opaque but, better quality chrysoprase
can also be transluscent. The lustre of this gemstone can best be
described as vitreous to resinous.
Chrysoprase is quite often opaque, however the more translucent
the gemstone the better the quality. There is a very minute quantity
of chrysoprase mined that is semi transparent to transparent and this
is very highly valued. However most of the good quality commercially
traded chrysoprase gemstone is translucent. Chrysoprase from Australia
is very easy to work on and takes a fine polish. Good quality chrysoprase
would be medium green, tending towards apple green. It would be without
cavities and inclusions.
Chrysoprase is very often referred to as Australian Jade. However
this is not true and chrysoprase is not jade. Green jade consists
of two main categories of gems, one is nephrite and the other jadeite.
Chrysoprase however belongs to neither nephrite nor jadeite, it is
basically a variety of chalcedony. Good quality chrysoprase can look
a lot like high grade jadeite (green jade) but chemically they are
poles apart. Chrysoprase is a gorgeous gemstone in it's own right,
but don't get fooled into believing that it is jade.
In recent years this gemstone has been used in all types of jewelry
from southwest jewelry to Victorian jewelry.
CITRINE & Citrine Gemstones
Citrine is a member of the Quartz species. It is so named due
to it's lemon yellow color. Colored by it's iron content, natural
specimens are quite rare. Commercial Citrines these days are most
likely heat treated Amethyst or Smoky Quartz. Mostly all of heat treated
citrines have a slight reddish tint to them. Pale yellow generally
denotes a natural stone. In recent years this gemstone has been used
in all types of jewelry from southwest jewelry to Victorian jewelry.
Natural-colored citrines are mined from Madagascar, Brazil, Argentina,
Burma, Namibia, Russia, Scotland, Spain and the United States.
MEDITERRANEAN CORAL & Coral Gemstones
Coral is one of the world’s few organic gems. The oldest known
findings of red coral date from the Mesopotamian civilization from
about 3000 B.C. Coral is formed from a colony of marine invertebrates,
primarily a skeletal calcium carbonate gem. The formations as seen
in the water look like tree branches. Many colors and varieties of
coral are found in warm coastal waters from around the world. Coral
varies in color: white, pink, orange, red and black. The rarest variety
is the blood coral or oxblood coral. This is a very deep red variety.
The best oxblood coral comes from the Mediterranean Sea. Coral is
usually cabochon cut. Because of its calcium composition coral should
not come in contact with acid such as vinegar. Coral has been
a staple in Southwest jewelry for decades.
DIAMONDS
Probably the best known gemstone in the world, diamonds have long
since been a very valuable item to own. So hard that it constitutes
the highest range of "10" on the Mohs' Hardness Scale. Diamond
chips that are not of gem quality are often used for the tips of drill
bits because of their durability. This hardness is one reason that
jewelers find this one of the most difficult gems to cut into a faceted
stone, but also one of the most profitable.
A wonderfully beautiful stone when faceted, the refractions from
it's many possible cuts make it a favorite of jewelers and customers
the world over.
In the past, because of their high cost, many diamond imitations
have been tried to duplicate the look for a lesser cost. Natural Zircons
were often used as well as other natural colorless specimens of rock
crystal, precious beryl, topaz and sapphire to imitate the look or
deceive unsuspecting buyers. A most common alternative these days
is the lab created Cubic Zirconia, which is shown in the picture above,
as it can closely resemble colorless diamonds for a fraction of the
cost.
Natural diamonds can be found in a variety of colors. While colorless
diamonds are the most valuable, natural colored diamonds can increase
value if it is one of the rarer colors of green, red, blue or purple.
Yellow diamonds are the most common color found and are sometimes
referred to in the trade as "champagne" diamonds.
Diamonds are graded for things like color, clarity, and cut. Inclusions
will affect clarity and generally degrade the perceived quality of
the stone. The cut of a diamond also affects the price as the complexity
of the cut will generally produce a better, more dazzling look, but
does add to the cost of preparing the stone.
Naturally colored diamonds are more valuable than treated ones,
but treatments like irradiation can change lesser quality diamonds
with multiple inclusions into more usable specimens for jewelry.
EMERALD
Emeralds are a member of the Beryl species. Considered a precious
stone, it's name has become synonymous with the deep rich green color
for which it is known. Chrome contained within is responsible for
it's brilliant coloring.
The very best emerald specimens are transparent, but many are
clouded by inclusions. Although all emeralds are brittle, stones can
be facetted, and most times are. Clear Emerald specimens are very
valuable.
FLOURITE CRYSTAL
Fluorite crystals, sometimes called Fluorspar, shows banded color
distribution as seen in the rainbow Fluorite Crystals pictured above.
Found in Germany, Burma, Argentina, England, France, Namibia, Austria,
Switzerland and the state of Illinois in the United States.
In recent years this gemstone has been used in all types of jewelry
from southwest jewelry to Victorian jewelry.
Fossil Mammoth Ivory & Ivory Gemstones
Among the treasures hidden for thousands of years in the remote
Arctic tundra of Alaska, Canada and Siberia are the massive ivory
tusks of the Woolly Mammoth, ruler of the prehistoric savanna. Larger
than today's Indian elephant, their tusks could weigh up to 300 pounds
each and measure over 16 feet in length. These great beasts ultimately
succumbed to the drastic climate changes accompanying great ice ages.
The skeletons and tusks were naturally interred for eons in the frozen
earth. We bring this hidden treasure to you as a beautiful gem alternative
to new elephant ivory.
These massive tusks are unearthed many ways. Modern day gold miners
dredge up mineralized remains in the course of placer mining activities.
We unearth fossil ivory during road construction. Bush pilots spot
the huge tusks jutting from ever eroding river banks while flying
over the tundra. Wilderness explorers find the tusks in the melting
muskeg. Regardless of the happy surprise of discovery, all of our
ivory is mined in accordance with all applicable federal and state
regulations.
The beautiful hues of tan, brown and blue are a result of thousands
of years of mineralization. Exact hues depend upon the mineral deposits
in the immediate soil surrounding the fallen mammoth. Thus, when processing,
each tusk reveals a unique character, never duplicated in another
piece of fossil tusks.
International trade in elephant ivory has been largely shut down
due to concern for the preservation of a living species. Much to the
delight of fine jewelry collectors, fossil mammoth ivory has emerged
as an eco-friendly and increasingly valuable alternative. While still
scarce and difficult to work with, this lustrous natural ivory possesses
the same gem qualities of new ivory, without the stigma attached to
illegal harvesting of endangered elephants.
Our supplier has searched out these prized fossils to transform
the ancient ivory into lustrous jewelry that reflect the hues of the
Arctic landscape. Their skilled craftsmen in Hong Kong, an internationally
recognized center for ivory carving, carefully work with the fragile
tusks. Each item is painstakingly designed, carved, polished and finished
to enhance the unique color of our Arctic Ivory. As with all fine
gem quality ivory, the luster is enhanced with frequent exposure to
one's natural skin oils, developing a rich patina over time. Ivory
has become a huge gem in the southwest jewelry circle, especially
used in zuni inlay jewelry.
FOSSILIZED CORAL REEF & Coral Gemstones
The differential nature of uplifted fossilized coral reef on the
western end of Roatan Island, Honduras is representative of the ongoing
earthquake activity of subsidiary faults along the American/Caribbean
plate boundary in Central America. Surveying elevations and mapping
the distribution of fringing coral reefs, fossil reefs, wave cut terraces,
exposed beach rock, beach sediments, and cave dripstones that have
been uplifted and/or tilted by fault movements was performed in an
area of approximately 10km2. At five dispersed locations subsurface
samples were taken down to a depth of 2.5m. These samples were analyzed
by XRD and ESR at intervals of 20cm. Ohio State Universitys
Nuclear Reactor Lab analyzed selected samples for U, Th, and K content,
and also irradiated annealed samples at six intervals of intensity.
The irradiated samples were used to establish a regression curve of
radiation exposure to ESR signal. Using radionuclide content and this
regression curve, ESR signals of field samples were analyzed to estimate
their crystallization and/or recrystallization ages. All ESR signals
of the field samples were below the limit of resolution of the regression
curve (i.e. >20k years). Recrystallization of the coral may have
accompanied differential uplift across the study area. Locally as
much as 10m of relief can be observed in the beach rock terraces that
trend from sea level in the southwest to over 10m in the northeast
segment. Differential local and regional uplift coupled with sea level
variability have influenced coastal geology and morphology in the
study area, and obtaining quantitative results has proved problematic.
In recent years this gemstone has been used in all types of jewelry
from southwest jewelry to Victorian jewelry.
FOSSILIZED DINOSAUR BONE
If fossilization was simply replacement of bone with stone, fossil
and living bones wouldn't be as chemically similar as they are, and
the intricate details found in fossilized dinosaur bones would not
have survived. Even more intriguing is the fact that some of the proteins
in bone have survived the fossilization process, in dinosaurs and
"older" fossils, a fact very consistent with a young earth.
Fossilization is essentially a process of denaturing bone, similar
to the denaturing of animal skin in leather manufacturing. The mineral
that makes the live bone hard, apatite, combines with fluorine (in
groundwater) to form fluorapatite. The living tissue in bone (mostly
proteins such as collagen) largely decay away, and the resulting void
spaces get filled with mostly quartz minerals.
Fossilization takes place when the following steps, which nicely
fit a young-earth flood-geology context, occur.
I. Rapid burial to prevent immediate disintegration.
II. Rapid fluoridation and quartzification to spare the bone from
bacterial decay and percolating fluids while buried in the sediment.
Depending on the mineral content of the groundwater ("the fountains
of the great deep" which "burst forth," [Gen. 7:11])
this could have occurred very rapidly. Experiments on buried shrimp
show that even soft tissue can be preserved in a matter of weeks under
the right conditions.
III. Survival of the bone through chemical change over time ("eons"
of survival required, of course, for evolutionists and long-age creationists).
Dinosaur Bone makes awesome jewelry, stunning yellows, reds, and
browns, with black. In recent years this gemstone has been
used in southwest jewelry and contemporary jewelry and is especially
popular in men's rings.
GARNETS & Garnet Gemstones
Garnet actually is a group of minerals with the same crystalline
structures which comes in a wide variety of colors. The different
varieties are detailed below. In recent years this gemstone has been
used in all types of jewelry from southwest jewelry to Victorian jewelry.
Pyrope Garnet: One of the most common varieties (pictured above),
it is red in color, often with a brownish tint to it. It has been
found in in Burma, Madagascar, China, Sri Lanka, South Africa, Tanzania
and the United States.
Rhodolite Garnet: Purplish red or rose-colored garnet.
Almandite Garnet: Named based on the town it was found in, this stone
is red with a violet tint. Mined from deposits in India, Brazil, Madagascar
and in the United States.
Spessartine Garnet: Also called Spessartite. Named from the word for
"forest" where they were found in Germany. It's color is
orange to red-brown. Also found in Burma, Brazil, Kenya, China, Sri
Lanka, Madagascar, Tanzania and the United States.
Tsavorite Garnet: Green to emerald green in color. The best specimens
are clear and are often faceted in emerald cuts. Found in Tanzania
and Kenya.
GASPEITE & Gaspeite Gemstones
Gaspeite was discovered in 1966 in the Lemieux Township of the
Gaspe’ Peninsula, Quebec, Canada. It is also found in western Australia
– the best from North of Perth, Australia. It is found as a secondary
mineral around nickel sulfide deposits. Gaspeite comes in light green
to an unmistakable apple green color. Gaspiete is usually cut into
cabochons. A light, almost apple green color is quite unique
and some varieties are almost a neon green. It may contain tan to
brownish patches of matrix which gives it a distinctive character.
This stone is named for the location of the original discovery in
Gaspe Peninsula, Quebec, Canada where material was found that was
NOT suitable for the jewelry industry. We only have one source for
this treasured stone and he tells us that the last discovery of "cuttable"
material (meaning hard enough and of good quality for use in jewelry
& beads) was in 1990 in Weegemoogha, Australia. This discovery
was a 40 ton block of Gaspeite, with only 27 tons of cuttable material,
so YES the availability of this stone will eventually run out to the
jewelry industry. It is considered both RARE and collectable. Gaspeite
has a hardness of 5.
Chemistry: (Ni, Mg, Fe)CO3, Nickel Magnesium Iron Carbonate
Class: Carbonate
Group: Calcite
Gaspeite is found as a secondary mineral around nickel sulfide
deposits. It was thought of as just a gangue mineral by miners when
it was encountered and usually placed in the mines dumps or tailings.
A gangue mineral is a mineral that probably contains the ore metal,
but its chemistry is such that processing it is either impossible
or unprofitable. Such was the case with gaspeite despite being rich
in nickel. Of course lapidary craftsmen have a different view of gaspeite's
profitability! Gaspeite is named for its type locality of Gaspe' Peninsula,
Lemieux Township, Gaspe'-ouest County, Quebec, Canada, but the best
material of late is coming from North of Perth, Australia. In recent
years this gemstone has been used in all types of jewelry from southwest
jewelry to Victorian jewelry.
PHYSICAL CHARACTERISTICS:
Color is a pale green to apple green.
Luster is vitreous to dull.
Transparency: Crystals are usually translucent, massive material is
opaque.
Crystal System is trigonal; bar 3 2/m.
Crystal Habits include rhombohedrons and scalenohedrons, but crystals
are very rare. More commonly found massive.
Cleavage is perfect in 3 directions forming rhombohedrons.
Fracture is uneven.
Hardness is 4.5 - 5.
Specific Gravity is 3.7 (somewhat heavy for a translucent mineral).
Streak is yellowish green.
Other Characteristics: Effervesces slightly in hydrochloric acid.
Associated Minerals include millerite, pentlandite, skutterudite,
annabergite and other nickel minerals.
Notable Occurrences include the type locality of Gaspe' Peninsula,
Lemieux Township, Gaspe'-ouest County, Quebec and Sudbury, Ontario,
Canada and a new source of carvable material from Kambalda and Widgie
Mooltha which is North of Perth, Australia.
Best Field Indicators are color, locality, reaction to acids, cleavage
and density.
HEMATITE & Hematite Gemstones
Known in some countries as "bloodstone" because of the
color it changes the cooling water of saw blades when it's cut, it
often resembles metal when polished. The sample above is a Specular
Hematite variety with shining specks. When pieces are sliced thin
enough, they appear red and transparent. Deposits are found in Bangladesh,
England, Brazil, China, Czech Republic, New Zealand and the state
of Minnesota in the U.S.A. This gemstone has become extremely popular
in beads.
HEMIMORPHITE
Chemistry: Zn4 Si2 O7 (OH)2 -H2O, Hydrated Zinc Silicate Hydroxide.
Class: Silicates
Subclass: Sorosilicates
Uses: minor ore of zinc
Specimens
Hemimorphite is one of the more common sorosilicates. Its most noteworthy
characteristic is its polar or hemimorphic crystals from where it
gets its name. The crystal structure produces a different termination
at each end of the crystal. One termination, the "bottom"
is rather blunt being dominated by a pedion face while the opposite
end, the "top" is terminated by the point of a pyramid.
The crystal structure contains tetrahedrons of ZnO3 OH, interlocked
with Si2 O7 groups and water molecules. The zinc is at the center
of the tetrahedron while the three oxygens, along with an OH group,
are at the four points of the tetrahedron. These tetrahedrons are
all aligned in the same direction with one face parallel to the pedion
termination and the "top" of the tetrahedrons pointing toward
the pyramidal termination.
Hemimorphite was originally named calamine but this name had been
used for another mineral and hemimorphite was proposed and is now
in wide spread use. The hemi means half while the morph means shape
and thus hemimorphite is aptly named. Only a few other minerals show
hemimorphic character such as tourmaline, but none show it as well
as hemimorphite. Clusters of hemimorphite that show well shaped crystals
do not always show the hemimorphic character. Because the crystals
of a single specimen tend to grow outward with either the "top"
or the "bottom" as the overall orientation for that specimen.
In order to see the hemimorphic character either a doubly terminated
specimen is necessary or two different clusters with different orientations
will be needed.
Specimens of hemimorphite tend to be of two very different forms
(seems like a trend with this mineral). One form produces very glassy,
clear or white, thin, bladed crystals, often well formed showing many
crystal faces. Many times these crystals are arranged in fan shaped
aggregates. The other form produces a blue to blue-green botryoidal
crust that resembles smithsonite or prehnite. Prehnite has a lower
density and is usually greener and has different associations with
other minerals. Smithsonite has a shimering luster that causes a play
of light across the rounded surfaces and has a higher density that
hemimorphite. Often hemimorphite will show rough crystal ridges or
"cock's comb" structures over top of the basic botryoidal
crust. For a collector both forms are a must in their mineral collections.
This gemstone has become extremely popular in beads.
HONEYCOMB CALCITE
Honeycomb Calcite is a beautiful and impressive form of calcite
mined exclusively in the state of Utah. Much like onyx and marble
it can provide a colorful replacement or a dramatic accent stone for
architectural & artistic applications. The name comes from the
remarkable honeycomb appearance when viewing a polished surface. It
is formed by the growth of long fibrous tubular cells and crystals
of honey color outlined by white membranes surrounding each cell.
The Coloring is attributed to iron deposits at the time of formation.
This gemstone has become extremely popular in beads.
HOWLITE & Howlite Gemstones
Howlite is a white colored stone usually with black matrix. Howlite
is often presented in it's dyed form, as shown above. Sometimes used
to imitate turquoise, it's natural black or brown veining lends itself
well to this. Naturally occurring in snow white coloring, which in
this form it is often passed off as white turquoise or "white
buffalo". This is one popular stone in the southwest jewelry
business.. the most common turquoise imitator these days as well as
natural.
IOLITE & Iolite Gemstones
Iolite is normally violet-blue in color, albeit, a sometimes dull
blue. The best quality faceted gems can sometimes resemble tanzanite
or sapphires. Prior to the 1980s, it was not readily available, but
supply has increased, making it a beautiful addition to most jewelry.
It's name is derived from the Greek word for violet. Sometimes
misleadingly called a "Water Sapphire" because it looks
clear and watery from the side, but can resemble a sapphire when looking
at it head on.
Iolite was used by the Vikings on cloudy days as a sort of compass.
They were able to locate the position of the sun by looking through
thin, clear slices of it. It has properties that acted like a light
polarizer and canceled out the mist and haze in the atmosphere. In
recent years this gemstone has been used in all types of jewelry from
southwest jewelry to Victorian jewelry.
Deposits are found in Sri Lanka, India, Brazil, Burma, Madagascar,
Tanzania and the United States
JADE & Jade Gemstones
There have been some civilizations in the South Pacific, Asia
and Central America where Jade has been more prized than Diamonds
or Gold. It is a very beautiful, yet tough stone that is resistant
to chipping and breakage. The ancient Chinese philosopher Confucius
said it was valuable because it represented the whole of purity, sureness
of intelligence, music and loyalty due to it's characteristics. Today
it is worn by many Asians for good luck and health.
The name "Jade" came from the Spanish conquistadors
who named it according to the job that native Mexicans were using
it for. As it was thought by them to relieve kidney ailments, the
Spanish named it "piedra de ijada" which meant "stone
of the loins." Eventually the Spanish term evolved into "Jade."
The early Roman civilization also considered it to be a good treatment
for kidney ailments such as nephritis (kidney inflammation) leading
to it being named "lapis nephriticus" for "stone of
nephrite." The Latin term was subsequently reduced to "nephrite"
and is sometimes used as an alternate name of Jade.
A French chemist, Augustine Damour, noted in 1863 that jade was
two different minerals. She used the word "Jadeite" for
Burmese jade to distinguish it from the Chinese jade "nephrite."
The Chinese had know of the difference between the two since the early
seventeen hundreds.
Jadeite and Nephrite are both comprised of tightly interlocking
crystals, which is different from the single crystals that comprise
most other gems.
Jadeite is a little bit harder and denser and can take more time
to polish. It is comprised of crystals which tend to be somewhat more
granular and coarse. In recent years this gemstone has been used in
all types of jewelry from southwest jewelry to Victorian jewelry.
Nephrite is most common and typically found in olive or forest
green. The oldest known sources come from China. It is slightly stronger
since it's crystal components are more intergrown than Jadeite.
VARIETY INFORMATION:
VARIETY OF: both jadeite and nephrite
USES: Gemstone and ornamental stone.
COLOR: shades of emerald green as well as white, gray, yellow, orange
and violet.
INDEX OF REFRACTION: is approximately 1.66 (jadeite) and 1.62 (nephrite)
HARDNESS: 6.5 - 7
CLEAVAGE: does not apply due to massive nature of jade
CRYSTAL SYSTEM: monoclinic
SPECIMENS
JASPER & Jasper Gemstones
A member of the Chalcedony species, Jasper comes in many different
varieties. It's is derived from the Greek word which means "spotted
stone." This dense, finely grained stone, can contain up to 20
percent foreign materials which actually determines it's color streak
and appearance for categorization. In recent years this gemstone has
been used in all types of jewelry from southwest jewelry to
Victorian
jewelry.
Jasper is found worldwide and comes in colors like red, brown,
yellow, gray and green. Black and Blue are the most rare colors found.
It comes in many varieties, Agate, Banded, Basanite, Egyptian, Hornstone,
Leopard Skin, Moukaite, Picture, Plasma, Scenic, & Zebra Jasper.
JET & Jet Gemstones
Jet is Anthracite Coal which is a sedimentary rock formed from
plants that lived millions of years ago. Jet is used a great deal
in contemporary and traditional Native American inlay jewelry.
KYANITE & Kyanite Gemstones
It's name is derived from the Greek word for blue. It can often
have inclusions and streaks. Having a variable hardness makes it quite
difficult to cut. This gemstone has become very popular in beads.
Mined from Brazil, Burma, Kenya, Austria, Zimbabwe, Switzerland and
the United States.
LABRADORITE & Labradorite Gemstones
Named after the peninsula in Canada where it was originally found,
it's a member of the Feldspar group. Specifically, plagioclase feldspar.
It has a luminescent quality, similar to a moonstone, but with more
of a streaked design of blues and greens. Some specimens show a more
complete rainbow spectrum as well. This quality is best seen when
the stone is in just the right direction in relation to the light
source because of the distortion created by the microscopic exsoluction
lamellae of high and low calcium plagioclase phases. In recent years
this gemstone has been used in all types of jewelry from southwest
jewelry to Victorian jewelry.
Deposits are obtained from Canada, Madagascar, Australia, Russia,
Mexico and the United States.
LAPIS LAZULI & Lapis Gemstones
Lapis has been highly prized since ancient Babylonian and Egyptian
times. Genuine lapis is a natural blue, opaque stone. It is brilliant
deep blue and sometimes possesses small sparkling gold or silver colored
flecks which are pyrite inclusions. The best lapis comes from Afghanistan
and Argentina. It can also be found in Russia, Chile, Canada and occasionally
the U.S. In recent years this gemstone has been used in all types
of jewelry from southwest jewelry to Victorian jewelry and is extremely
popular in the zuni inlay jewelry.
LION'S PAW SHELL
Lion's Paw Shell similar to Spiny Oyster comes from Baja Mexico.
The interior of the shell has less white and these shells can be orange
on one side with purple on the inside thus they make wonderful beads
purple and orange, as well as cabochons. In recent years this gemstone
has been used in all types of jewelry from southwest jewelry to
Victorian
jewelry.
MALACHITE & Malachite
Gemstones
Malachite is named for the Greek word “mallow” which is a green
herb. Malachite is a copper ore that comes in a brilliant green marked
with bands of contrasting shades of the same green. Malachite is often
found in copper producing areas such as Russia, Mexico, Australia,
England, Southwest US and notably Zaire is a major producer today.
Never clean malachite with any product containing ammonia. In recent
years this gemstone has been used in all types of jewelry from southwest
jewelry to Victorian jewelry and is extremely popular in zuni inlay
jewelry.
MOTHER OF PEARL
Mother of Pearl is a hard, iridescent inner layer of certain
shells such as abalone, pearl oyster and mussel. Mother of pearl varies
in shades of white, yellow, pink and gray. Care should be taken not
to expose it to chemicals. In recent years this gemstone has been used
in all types of jewelry from southwest jewelry to Victorian jewelry.
MOONSTONE & Moonstone Gemstones
Moonstones come in a variety of colors, ranging from colorless
to white, gray, brown, yellow, orange, green, or pink. Clarity ranges
from transparent to translucent.
Description: (K, Na) AlSi3O8, Moonstone (also called rainbow moonstone)
is soft milky white stone, the most valuable variety of feldspar with
an rainbow sheen. Moonstone shows a silvery or bluish iridescence,
that is caused by the intergrowth of two different types of feldspar
with different refractive indexes. The term moonstone also has been
applied to the plagioclase feldspars peristerite and labradorite,
which also exhibit iridescence.
The name's origin: The moonstone named for its semblance in color
to the moon.
Moonstone was very popular with the Romans, who thought it was
formed out of moonlight, also used in Roman jewelry since 100 AD.
In India moonstone is considered a sacred stone to this day. In recent
years this gemstone has been used in all types of jewelry from southwest
jewelry to Victorian jewelry.
MUSCOVITE QUARTZITE
Art Smith, Mineralogist-Geologist wrote: I did a microscopic examination
of the bead material that you call Muscovite. It is a natural stone,
probably a metamorphic rock called quartzite. It is composed of well-fused
grains of clear to slightly cloudy quartz with interspersed flakes
of pale tan, slightly iron stained, mica that is probably muscovite.
The iron staining seems to be most concentrated on the edge of the
muscovite flakes and so emphasizes them when the stone is polished.
This is an excellent hard and durable stone that will make good beads,
cabochons or other lapidary items. This gemstone had become very popular
in beads and bead jewelry.
OPAL & Opal Gemstones
Opal is a paradoxical gemstone, and one of the most fascinating.
It is a form of quartz, but is not a form of quartz. Quartz is very
common, yet has many rare and precious gem varieties. Opal itself
has numerous varieties. It is the most colorful gemstone, but some
forms are colorless. It can be very bright and beautiful, and it
can be dull and dead. It is best known for its flashes of color,
but some varieties have no flashes of color, and are still opals.
It can be black, and it can be white. Its best known attribute, the
brilliant flashes of many colors, are not called opalescence, but
iridescence. Some people think opal is unlucky, but it is one of
the most valuable and desirable of gems. Actually because opal is
a gel, it is, strictly speaking, not a form of quartz. Quartz is a
crystalline form of silicon dioxide, opal is a solid gel. However
because the chemical formula is the same except that opal is hydrous,
that is it contains some water which is chemically attached to the
silicon dioxide molecules. Opals were known and mined in Roman
times. The Roman mines were in and around Cervenica, previously in
Czechoslovakia, although we have now lost track of all the recent
changes in Balkan geography. Now most the opal the market is from
Australia or Mexico. Australian opal is the finest. This gemstone
has been used in all types of jewelry from southwest jewelry to
Victorian
jewelry for decades, and is one of the most popular gemstones on the
market.
PEARLS & Pearl Gemstones
Color: The color of pearls varies with the mollusk and its environment.
It ranges from black to white, with the rose of Indian pearls esteemed
most. Other colors are cream, gray, blue, yellow, lavender, green,
and mauve. All occur in delicate shades.
Cultured pearls are being produced in virtually every color of the
rainbow.
Description: The chief component of the nacre that constitutes
the pearl is aragonite CaCO.
Pearls are formed by a mollusk consisting of the same material (called
nacre, or mother-of-pearl) as the mollusk's shell. It is a highly
valued gemstone.
The shell-secreting cells of the mollusk are located in the mantleof
its body. When a foreign particle penetrates the mantle, the cells
attach to the particle and build up more or less concentric layers
of pearl around it. Irregularly shaped pearls called baroque pearls
are those that have grown in muscular tissue. Pearls that grow adjacent
to the shell are often flat on one side and are called blister pearls.
Pearls are characterized by their translucence and lustre and by a
delicate play of surface color called orient. The more perfect its
shape (spherical or droplike) and the deeper its lustre, the greater
its value. Only those pearls produced by mollusks whose shells are
lined with mother-of-pearl (e.g., certain species of both saltwater
oysters and freshwater clams) are really fine pearls. Pearls from
other mollusks are reddish or whitish, porcellaneous, or lacking in
pearly luster.
The surface of a pearl is rough to the touch. Pearls come in a wide
range of sizes. Those weighing less than 1/4 grain (1 pearl grain
= 50 milligrams = 1/4 carat) are called seed pearls. The largest naturally
occurring pearls are the baroque pearls; one such pearl is known to
have weighed 1,860 grains.
Cultured pearl is natural but cultivated pearl produced by a mollusk
after the intentional introduction of a foreign object inside the
creature's shell.
The discovery that pearls could be cultivated in freshwater mussels
is said to have been made in 13th-century China, and the Chinese have
been adept for hundreds of years at cultivating pearls by opening
the mussel's shell and inserting into it small pellets of mud or tiny
bosses of wood, bone, or metal and returning the mussel to its bed
for about three years to await the maturation of a pearl formation.
Cultured pearls of China have been almost exclusively blister pearls.
The production of whole cultured pearls was perfected by the Japanese.
The research that led to the establishment of the industry was started
in the 1890s by Mikimoto Kokichi, who, after long experimentation,
concluded that a very small mother-of-pearl bead introduced into the
mollusk's tissue was the most successful stimulant to pearl production.
Cultured pearls closely approximate natural pearls.
The finest Oriental pearls are found in the Persian Gulf. Other notable
sources of fine-quality pearls include the Gulf of Mannar between
India and Sri Lanka, the waters off Celebes, Indonesia, and the islands
of the South Pacific. In the Americas, the Gulf of California, the
Gulf of Mexico, and the waters of the Pacific coast of Mexico have
yielded dark-hued pearls with a metallic sheen as well as white pearls
of good quality.
Freshwater mussels in the temperate zone of the Northern Hemisphere
have produced pearls of great value, as for example those from the
Mississippi River. Pearling is a carefully fostered industry in central
Europe, and the forest streams of Bavaria, in particular, are the
source of choice pearls. Freshwater pearling in China has been known
from before 1000 BC.
Cultured pearls: Northern Australia established its first cultured
pearl farms in the 1960s, that by the mid-1970s were an established
industry, producing pearl shell as well as pearls. Japan and Australia
are the largest producers of cultured pearls, though Fiji also produces
some.
PEITERSITE & Peitersite Gemstones
PIETERSITE is a chatoyant, quartz and crocidolite asbestos. Its
appearance is quite different because it's been broken into fragments
(brecciated), stirred around if you will, and recemented by silica.
The fibers are wavy unlike the gold tiger eye that normally has straight
fibers. The resulting patchwork is in shades of blues, yellows, greens,
brown, and reds Sometimes areas with clear quartz is also found and
I like to cut stones leaving some of the water clear quartz areas
when I find them..
Pietersite is named for Sid Pieters, a well-known gem and mineral
dealer is from Windhoek, Namibia who imported it to Idar in the 1970s.
One of the major sources of Pietersite is Namibia, an area about
2,000 miles from the tigereye locality in South Africa. It was found
as rounded cobbles in the soil on a farm in the neighborhood of Outjo,
in the Kuraman district, but its actual source has never been located.
It is also reported that it has become vary scarce in Africa and South
African authority Windisch says it is all mined out and rarely
available
from "old" stock.
The other major source of Pietersite is from the Henan Province
of China. It made its appearance on the open market in the late 1990's.
It was originally found in the 1950's but no one considered using
it for jewelry-making. The Chinese had no idea how popular it would
become in the rest of the world. This pietersite is very similar to
that found in Nambia except that it has more red and golden-red combinations
and is narmally more fractured from my experience with the rough.
The Chinese material contains both chrysotile and crocidolite
fibers and petrification is very strong. Unfortunately, as the material
gets popular, the source is being exhausted and one mine has been
reported to have had to close due to ground water flooding it. In
recent years this gemstone has been used in all types of jewelry from
southwest jewelry to Victorian jewelry.
PERIDOT & Peridot Gemstones
Peridot (pronounced pair-a-doe) is the gem variety of olivine.
Olivine, which is actually not an official mineral, is composed of
two minerals: fayalite and forsterite. Fayalite is the iron rich member
with a pure formula of Fe2SiO4. Forsterite is the magnesium rich member
with a pure formula of Mg2SiO4. Olivine's formula is written as (Mg,
Fe)2SiO4 to show the substitution of the magnesium and iron. Peridot
is usually closer to forsterite than fayalite in composition although
iron is the coloring agent for peridot. The best colored peridot has
an iron percentage of less than 15% and includes nickel and chromium
as trace elements that may also contribute to the best peridot color.
Gem quality peridot comes from the ancient source of Zagbargad (Zebirget)
Island in the Red Sea off the coast of Egypt; Mogok, Myanmar (formerly
known as Burma); Kohistan, Pakistan; Minas Gerais, Brazil; Eifel,
Germany; Chihuahua, Mexico; Ethiopia; Australia; Peridot Mesa, San
Carlos Apache Reservation, Gila County, Arizona and Salt Lake Crater,
Oahu, Hawaii, USA. The best quality peridot has historically come
either from Myanmar or Egypt. But new sources in Pakistan are challenging
that claim with some exceptional specimens. The Arizona gem material
is of lesser quality, but is far more abundant and is therefore much
more affordable. An estimated 80 - 95% of all world production of
peridot comes from Arizona. The Myanmar, Pakistani and Egyptian gems
are rarer and of better quality and thus quite valuable approaching
the per carat values of top gemstones. Possibly the most unusual peridot
is that which comes from iron-nickel meteorites called pallasites.
Some are actually facetted and set in jewelry.
Peridot is perhaps derived from the French word peritot which
means unclear, probably due to the inclusions and cloudy nature of
large stones. It could also be named from the Arabic word faridat
which means gem. In either case, peridot has been mined as a gemstone
for an estimated four thousand years or better, and is mentioned in
the Bible under the Hebrew name of pitdah. Peridot gems along with
other gems were probably used in the fabled Breastplates of the Jewish
High Priest, artifacts that have never been found. The Greeks and
Romans referred to peridot as topazion and topazius respectively and
this name was later given to topaz, to end the confusion with the
two gems. Historical legend has it that peridot was the favorite gemstone
of Cleopatra. Pliny wrote about the green stone from Zagbargad Island
in 1500 B.C.. Even until recently have jewelers used the term "chrysolite"
(latin for golden stone) in referring to peridot gems for some reason.
This term has also been used to refer to other gemstones, of a more
golden color.
Zagbargad (Zebirget) Island has been known as St John's Island
and was mined for centuries. Before World War I, this island was extensively
mined and produced millions of dollars worth of gems. Since then the
mining has been off and on and at present is all but nonexistent.
Still, specimens from here are available at times and it certainly
is a classic mineral locality.
Throughout time, peridot has been confused with many other gemstones,
even emerald. Many "emeralds" of royal treasures have turned
out to be peridots! And although peridot is distinctly a different
shade of green, many jewelers refer to peridot as "evening emerald".
Emerald is a dark green as opposed to a yellow green and always contains
inclusions. Other green gemstones confused with peridot include apatite
(which is much softer); green garnets (have no double refraction),
green tourmaline and green sinhalite (both of which are strongly pleochroic),
moldavites (no double refraction) and green zircon (significantly
heavier). All of these gemstones rarely have as nice a yellow component
to their green color as does most peridot, but darker green peridot
can be confusing when good crystal form is not discernible.
Peridot is a beautiful gemstone in its own right and is widely
popular. Its popularity is said to be increasing yearly and with new
finds in Pakistan producing exceptionally well crystallized specimens,
peridot can be fun to collect for years to come.
PETRIFIED WOOD
Petrified wood consists of a wide variety of minerals including
silica, silicates, carbonates, sulfates, sulfides, oxides, and phosphates.
They all can permineralize wood to form petrified wood (Adams 1920).
However, petrified wood most commonly consists of silica (Si02) in
the form of either opal or chert (Stein 1982).
Silicified wood is usually found within one of two types of strata.
First, it occurs within accumulations of volcanic ash, tuff, and breccia,
e.g. the petrified forests of Yellowstone National Park. Second, silicified
wood also occurs within sands, silts, and muds deposited by rivers
and streams that have hardened to sandstones, siltstones, and shale.
Typically, the sandstones, siltstones, and shales that contain silicified
wood also contain redeposited tuffaceous materials or volcanic ash.
The silicified wood found in Petrified Forest National Park in Arizona
and the Miocene strata of Louisiana and Texas occur within such strata
(Knauth 1972:44).
Origin of Petrified Wood
Silicified wood forms in these deposits, because of the presence of
dissolved silica within the groundwater. The silica is derived from
the dissolution of the volcanic material by the groundwater within
the volcanics or sediments. This dissolved silica in the form of monomeric
silicic acid attaches itself to the lignin and cellulose of the wood.
With time, a layer of the monomeric silicic acid forms on the exposed
woody tissues. The monomeric silicic acid dehydrates into silica gel.
Additional layers of the monomeric silicic acid attach to this silica
gel eventually filling and encasing the wood with silica gel. A rapid
loss of water converts the silica gel into amorphous silica (opal)
(Leo and Barghoorn 1976; Scurfield and Segnit 1984).
Within 10 to 40 million years, the opal of the silicified wood
further dehydrates and crystallizes into microcrystalline quartz (chert).
Factors such as temperature and pressure may speed or slow the process,
but eventually the opal of the silicified wood becomes chert (Stein
1982). During the change from opal to chert in silicified wood, the
relict woody texture may either be retained or lost.
During the silicification process, various materials and minerals
may be incorporated into the silica gel. For example, manganese dioxides,
iron oxides, organic matter and authegenic clay can alone or in combination
color the opal or chert that forms silicified wood. Because each piece
of wood becomes silicified in its own local geochemical environment,
the trace and major materials and elements that it contains will vary
greatly from piece to piece even within the same stratum (Knauth 1972:45;
1981). Therefore, trace element analysis is generally useless in tracing
the source of any silicified wood.
Types Of Petrified Woods
Within the Tertiary strata that outcrop in southeast to southwest
Texas and into Louisiana, three types of silicified wood can be recognized.
They are rather nondescript silicified wood, palm wood, and a massive
silicified wood. The nondescript silicified wood consists of silicified
wood that possesses a recognizable woody structure. The relict woody
structure is fine and nondescript. It is not identifiable without
oriented thin sections, specialized references, and comparative material
(Blackwell et al. 1983:2). Therefore, this type is best described
just as "silicified wood".
The second type of silicified wood is commonly called including
the State Fossil "petrified palm wood" by geologists and
rock collectors. Palm wood is a group of fossil woods that contain
prominent rod-like structures within the regular grain of the silicified
wood. Depending upon the angle at which they are cut by fracture,
these rod-like structures show up as spots, tapering rods, or continuous
lines. The rod-like structures are sclerenchyma bundles that comprise
part of the woody tissues that gave vertical strength to the Oligocene
and Miocene tree genera, Palmoxylon (Blackwell et al. 1983:4-5).
The third type of silicified wood is massive silicified wood.
The silicification of the wood or subsequent transformation of silica
gel to opal or chert has obliterated any trace of the grain of the
former wood. The destruction of the structure of the silicified wood
has resulted in a massive opal or chert that lacks any visible indication
of its origin. Because of its variable, massive nature and heterogeneous
trace element composition, many investigators, e.g. Jolly (1982) and
Jolly and Kerr (1984), have often failed to recognize the nature of
this material. The Eagle Hill Chert found within West-Central Louisiana
is a local, massive silicified wood (Heinrich 1984). A similar massive
silicified wood called "golden palm" occurs in equivalent
strata within East-Central Texas (Patterson 1985).
PICASSO MARBLE
A gorgeous stone native to southeastern Utah. Utah Picasso Marble
is a common building stone, it is a classic sculptors stone. Some
marbles are famous such as Italian white and Belgian black marble.
The colors vary and may be found in pinks, yellows, and browns. Marble
is a soft rock and yet dense in structure. It was once limestone in
the Precambrian era. The sedimentary limestone masses were sometimes
contacted by hot magnas and the pressure altered the limestone. Other
minerals from the magna then infiltrated the limestone causing feathery
lines and beautiful designs such as Picasso Marble found in Beaver
County, Utah. The scenic effect and color contrast in black and gold
has made this marble a popular cutting rock for the lapidarest. In
recent years this gemstone has been used in all types of jewelry from
southwest jewelry to Victorian jewelry.
RAINBOW CALSILICA
is a newly-found, multi-colored, layered stone composed of calcium
and silica from a mine in Chihuahua, Mexico. This stone has been recently
used for Zuni fetish carvings and in Native Indian jewelry. I am not
too sure of the reality of this stone, I have heard rumors that it
is just colored sand layered and treated like they treat turquoise.
In recent years this gemstone has been used in all types of jewelry
from southwest jewelry to Victorian jewelry.
RHODOCHROSITE & Rhodochrosite Gemstones
Rhodochrosite (whose name means rose-colored) is a very attractive
mineral with an absolutely one-of-a-kind, beautiful color. Although
it can be an ore of manganese, it is its ornamental and display specimen
qualities that make it a very popular mineral. The color of a single
crystal can just astound the observer with its vivid pink-rose color
that seems to be transmitted out of the crystal as if lit from within.
Individual crystals are found in well shaped rhombohedrons and more
rarely scalahedrons. In a massive form its pink and white bands are
extremely attractive and are often used in semi-precious jewelry.
Rhodochrosite is often carved into figurines and tubular stalactitic
forms are sliced into circles with concentric bands that are truly
unique in the mineral kingdom. Fine crystals are sometimes cut into
gemstones, but rhodochrosite's softness and brittleness limit it as
a gemstone for everyday use.
Identification of rhodochrosite is fairly easy despite a few similarly
colored minerals such as rhodonite. Rhodonite is harder and has different
cleavage; but perhaps the best distinguishing factor is its lack of
reaction to acids. Rhodochrosite will easily with show some reaction
to cold acids which demonstrates its carbonate chemistry. Basically,
any rose-pink carbonate is considered rhodochrosite; however some
calcites with a small amount of manganese impurities can be pink in
color. The manganese replaces some of the calciums in calcite but
a complete series between calcite and rhodochrosite is not established.
Differentiating pink calcite from rhodochrosite may require a fluorescence
test as rhodochrosite is distinctly non-fluorescent and manganese
is a fluorescent activator in calcite.
There are many localities for rhodochrosite that are of great
reknown. Beyond a doubt, the best locality for rhodochrosite is the
Sweet Home Mine in Colorado. It is unmatched for its superb rhodochrosite
crystals that exhibit the best features of the species; a fine bright
rose color and sharp well formed crystals. Some specimens from here
are quite large and of world class distinction.
Other localities have produced some fine specimens as well. Catamarca,
Argentina has an old Inca silver mine that has produced fine stalatitic
examples of rhodochrosite that are unique and very attractive. Cut
cross-sections reveal concentric bands of light and dark rose colored
layers. These specimens are carved and used for many ornamental purposes.
Mont Saint-Hilaire, Quebec, Canada has produced many fine rare
minerals but it also produces some nice rhodochrosite specimens as
well. Specimens from here are generally small, but have a good color
and are associated with rarer minerals.
There are many Peruvian rhodochrosite localities that have produced
a number of good specimens. These crystals are usually paler in color
than other specimens, but are accented by interesting metal sulfide
minerals.
N'Chwanging Mine, Hotazel, South Africa has produced possibly
the best examples of scalahedral crystals of rhodochrosite. The unusual
crystal habit is due in part to this being one of a few sedimentary
crystallizing environments for the species. Most other localities
are the result of metamorphism, late stage igneous intrusion or more
commonly hydrothermal precipitation. In recent years this gemstone
has been used in all types of jewelry from southwest jewelry to
Victorian
jewelry.
RHODONITE & Rhodonite Gemstones
Chemistry: (Mn, Fe, Mg, Ca)5(SiO3)5 , Manganese Iron Magnesium
Calcium Silicate.
Class: Silicates
Subclass: Inosilicates
Group: Pyroxenoid
Uses: ornamental and semi-precious stone and as a minor ore of manganese
Specimens
Rhodonite is an attractive mineral that is often carved and used in
jewelry. It is named after the Greek word for rose, rhodon. Its rose-pink
color is distinctive and can only be confused with rhodochrosite and
the rare mineral, pyroxmangite, MnSiO3. Rhodochrosite however is streaked
with white minerals such as calcite and is reactive to acids. While
rhodonite does not react to acids and is usually associated with black
manganese minerals and pyrite. Pyroxmangite is a little harder to
distinguish because the two minerals are closely related and x-ray
studies are usually needed when found massive. Crystals of pyroxmangite
are often twinned as is not the case with rhodochrosite crystals.
Crystals of rhodonite, while not in nearly the same abundance as massive
rhodonite, are still found and distributed on the mineral markets.
They come from a few notable localities and are considered classics
by collectors.
RUBY & Ruby Gemstones
Ruby is the red variety of corundum, the second hardest natural
mineral known to mankind. The non-red variety of corundum is Sapphire
Sapphires are well known among the general public as being blue, but
can be nearly any color. The red color in ruby is caused by trace
amounts of the element chromium. The best shade of red for ruby is
often given the name "pigeon blood red", but ruby can be
any shade of red up to almost pink.
Oriented rutile crystal inclusions cause a six-rayed-star light
effect (called asterism) to form the popular Star Ruby.
Rubies come from all over the world but good gemstones are found
at Thailand, India, Madagascar, Zimbabwe, North Carolina in the U.S.,
Afghanistan, Pakistan, Sri Lanka, Kenya, Tanzania, Kampuchea, and
perhaps most notably, Burma.
Rubies have a famous place in science - the first lasers were
made from artificial ruby crystals. They still are used for this purpose
although other materials offer improved efficiency. Some ruby crystals
show the fluorescence (actually very short term phosphorescence) that
makes a laser possible. Nothing is higher than Ruby in the Thai culture
for Jewelry.
SAPPHIRE & Sapphire Gemstones
Sapphire is the non-red variety of corundum, the second hardest
natural mineral known to mankind. The red variety of corundum is Ruby.
Sapphires are well known among the general public as being blue, but
it can be nearly any color, even colorless. White (or colorless but
massive) sapphire would more properly be called corundum. The blue
color is by far the most popular color for sapphire but orange-pink,
golden, white, and even black have generated much interest in the
gem trade. Oriented rutile crystal inclusions cause a six-pointed-star
light effect (called asterism to form the popular Star Sapphire. In
recent years this gemstone has been used in all types of jewelry from
southwest jewelry to Victorian jewelry.
VARIETY INFORMATION:
VARIETY OF: Corundum , Al2O3 .
USES: Gemstone.
BIRTHSTONE FOR: September
COLOR: various colors, except for red.
INDEX OF REFRACTION: 1.76 - 1.78
BIREFRINGENCE: 0.009
HARDNESS: 9
CLEAVAGE: none, although there is a rhombic parting
CRYSTAL SYSTEM: trigonal
PLEOCHROIC: strongly
SEPTARIAN NODULES
Utah Septarian Nodules Septarians were formed millions
of years ago when the Gulf of Mexico reached what is now Southern
Utah. Decomposing sea life, killed by volcanic eruptions, had a chemical
attraction for the sediment around them, forming mud balls. As the
ocean receded, the balls were left to dry and crack. Because of their
bentonite content they also shrank at the same time trapping the cracks
inside. As decomposed calcite from the shells was carried down into
the cracks in the mud balls, calcite crystals formed. A thin wall
of calcite was transformed into aragonite separating the bentonite
heavy clay exteriors from the calcite centers. Because of this, the
nodules are called Septarians.
SEREPHINITE
Hails from Russia and is the cousin of Charoite. Serephinite is
a relatively late comer to the marketplace, having been known only
since the mid 1980’s. The color of serephinite is described as a stunning
emerald, forest green with metallic looking chrystalline patterns
that look like a candy pant job on a car. The white chrystalline “needles”
give charoite a very distinctive appearance and depth often forming
a swirling pattern of interlocking crystals. Some call this look "chatoiant".
Serephinite is found in the