This huge Bisbee Turquoise Cabochon How’s it all, deep blue, Bisbee Turquoise with chocolate brown smoke and web matrix. It was cut by John Hartman from a natural turquoise rock. The stone weighs a whopping 118.cts. We do not treat Bisbee Turquoise that, we feel, is hard enough to cut a stable, durable gemstone. We are also mindful not to use any harsh chemicals in any of the cutting or processing of our Natural Bisbee Turquoise cabochons. John & Estell Hartman have been Bisbee Turquoise since the late 1960’s. John has been cutting Bisbee Turquoise Cabochons since 1972. There is no person that has cut and studied the Bisbee Turquoise mineral near as much as John, that is a fact!