Tiffany Stone - Delta, Utah

Contributed by: Chris Clemens
minID: WFH-933
Date: May 1st, 2026
Locality: Brush Wellman Mine, Spor Mountain Mining District, Thomas Range, Juab County, Utah, USA (See on Mindat)
Size: 9.4 x 4.8 x 14 cm
Weight: 604 g

Description:
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.

This example is a half nodule of Tiffany stone having a single cut surface, and it shows a colorful multi-wavelength fluorescent response that is typical for the material. The blue and purple fluorescence is due to the fluorite content; the bright green is uranyl-activated, evidenced by the low level of radioactivity emitted by this specimen (approximately 250 cpm).

The first set of photographs show the cut interior surface of the Tiffany stone specimen seen under visible light and various UV wavelengths. The second set of images show the natural exterior surface of the Tiffany stone nodule photographed under visible light and various UV wavelengths.

Originally posted by Chris Clemens on Nature's Rainbows in 2017.