RARE Tiffany Stone Utah 925 Sliver Pendant Gemstone Rare Natural Stone Tiffany Stone, Brush Wellman Mine, Delta, Utah (Closed) Tiffany stone is a complex rock composed of opalized fluorite with bands and veins of chalcedony, manganese oxide and bertrandite. The only known source for this rare material is the Brush Wellman beryllium mine, Spor Mountain, near Delta, Utah, where it is mined for its beryllium content. Due to its swirling colors of purple, lavender and cream, Tiffany stone is a popular lapidary material, and is often cut into cabochons and beads. Less known is that it is also brightly fluorescent under UV due to its fluorite and opal content