Ruby Crystals, Cascade Canyon, San Bernardino County, California
Contributed by: Chris Clemens
minID: NR7-GE4
Date: Apr 20th, 2026
Locality: Cascade Canyon, San Bernardino County, California, USA (See on Mindat)
Size: 71 x 44 x 85 mm
Weight: 261 g
Description:
Cascade Canyon is a little-known location situated in the San Gabriel Mountains, northeast of Los Angeles. The rocks of Cascade Canyon are primarily comprised of complexly deformed metamorphosed sedimentary rocks that are notable for their content of red/purple colored ruby crystals. This specimen contains numerous red/purple hexagonal crystals of corundum (ruby) that are found in a light tan colored, schistose matrix that is typical for Cascade Canyon. As seen in the following photograph, bright red fluorescent ruby crystals contrast against a weakly fluorescent matrix of metamorphic rock under longwave UV (365 nm).
Located near Mt. Baldy, most of the Cascade Canyon collecting area lies within the Angeles National Forest. Public collecting is allowed, but requires a permit, which is obtainable from the Forest Service.
Originally posted by Chris Clemens on Nature's Rainbows in 2019.
Summary of luminescence responses:
Corundum var. Ruby (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Red