Fluorescent Tremolite from the Land of the Greatest Snow on Earth
Contributed by: Chris Clemens
Date: Apr 27th, 2026
Locality: Alta, Little Cottonwood Mining District, Salt Lake County, Utah, USA (See on Mindat)
Size: 6.6 x 2.5 x 10.8 cm
Weight: 203 g
Description:
This is a very nice fluorescent specimen from a location that is near and dear to my heart. This piece contains small, bladed crystals of fluorescent tremolite in a non-fluorescent groundmass. Under shortwave UV the tremolite fluoresces bright blue/white. Collected from an unnamed mine in the Alta Mining District, Salt Lake County, Utah. Located in the upper reaches of Little Cottonwood Canyon in the Wasatch Mountains, the Alta area was the location of numerous prosperous silver mines that were active from the 1860s until the 1930s. In addition to numerous mine relics, old tunnels, and tailings piles, the area is now home to two world-class ski resorts- Alta and Snowbird. I spent hundreds of days skiing at these two resorts while living in nearby Salt Lake City. The Utah state motto "The Greatest Snow on Earth" is well deserved! The fluorescent mineral specimens aren't too bad either.
Originally posted by Chris Clemens on Nature's Rainbows in 2017.
Summary of luminescence responses:
Tremolite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Blue