Tiffany Stone

Tiffany Stone is found in Bertrandite deposits, an ore of beryllium but known as a gemstone for its beautiful purple colors. Tiffany stone can show other colors too including a peachy color and mauve color. Tiffany Stone is found at one mine in the world, in Utah USA, the Brush Wellman beryllium mine, in the Thomas Range at Spor Mountain. A very rare only gem material is what collectors and miners have been allowed to remove form the mine. the mine owner is much more interested in the beryllium. 

Believed to be an opalized fluorite, it is around a 4 on the mohs scale and often stabilized, however there is some that has opalized and is harder. Tiffany stone forms in veins and nodules along with fluorite and dolomite, it also occurs with quartz and opal. 

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.