Corundum – Cascade Canyon, Los Angeles County, California

Contributed by: Mark Cole
Date: Mar 23rd, 2026
Locality: Cascade Canyon, Los Angeles County, California, USA (See on Mindat)

Description:
Original locality given as Mt. Brady, but it looks like that was a mistake. No Mt. Brady in Los Angeles County. There is a Mt. Baldy (Mount San Antonio). Cascade Canyon is a well-known Corundum location in Los Angeles County, located 1.7 miles southwest of Mt. Baldy.

Originally posted by Mark Cole on Nature's Rainbows in 2015.

Fluorescence under longwave UV light.

Normal light. Closeup

Summary of luminescence responses:

Corundum var. Ruby (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Red