This is a nice big chunk of rough, natural & very rare Tiffany Stone.
Tiffany Stone / Opal Fluorite is a very rare stone of aesthetic and colorful patterns. The rarity and value of Tiffany Stone is a result of its locale. The only location where it has been found is at the Brush Wellman Beryllium Mine in the Topaz-Spor Mountains of Juab County's Sevier Desert, in Western Utah. As mining operations policies have been tightened there is very little of this truly unique stone left with all available stones either on the market or in the hands of private collectors, soon this rare and beautiful mineral will be unattainable, already it is exceptionally hard to find even for us!
Size: 85 x 70 x 50mm
"Tiffany stone" is a trade name used for a purple, blue and white gem material that can be cut and polished into beautiful beads, cabochons and tumbled stones. Geologically, Tiffany stone is a rock composed primarily of fluorite with smaller amounts of opal, calcite, dolomite, quartz, chalcedony, bertrandite and other materials. Other names used for Tiffany stone are "opalized fluorite," "ice cream stone," and "bertrandite."
Tiffany stone is a rare material. It is mined at one location worldwide - the Brush Wellman beryllium mine, at Spor Mountain, western Utah. It occurs there as nodules that are part of the ore produced at the mine. The nodules typically contain between one and two percent beryllium by weight.
The United States Geological Survey reports that the nodules are carbonate clasts that have been largely replaced by fluorite. Small amounts of bertrandite, a beryllium mineral with a chemical composition of Be4Si2O7(OH)2, occurs as submicroscopic grains within the fluorite.
Almost all of the Tiffany stone mined at Spor Mountain is crushed and used to produce beryllium. A small amount has been carried out of the mine by employees, and a small amount has been gathered by collectors who have rarely been allowed into the mine. These are the only sources of the gem material because Brush Wellman has always been interested in producing beryllium and has not been interested in Tiffany stone.
The most appropriate name for Tiffany stone is “opal fluorite” or “opalized fluorite.” These names reasonably represent the composition of most specimens. Another popular name is “bertrandite.” That name is incorrect because bertrandite is a mineral, which only comprises a few percent of the rock known as Tiffany stone. It is also called "ice cream stone" because of its delicious color.
There are numerous stories behind the name “Tiffany Stone.” Some people attribute the name to Tiffany and Company, the famous luxury goods retailer. The company has never been associated with the mine or with Tiffany stone. Others attribute the name to the daughter of a Brush Wellman employee who collected the colorful nodules brought home by her father. This story is possible, but the names of the miner or his daughter are not found in any written record.