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. As seen in the following photograph, the ruby crystals display bright red fluorescence under long wave UV. The specimen shown here is approximately 85 x 71 x 44 mm in size, and weighs 261 grams.
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.
Bright red fluorescent ruby crystals contrast against a weakly fluorescent matrix of metamorphic rock under long wave UV (365 nm).
Same specimen seen under visible light. In this typical example from Cascade Canyon, numerous red/purple hexagonal crystals of corundum (ruby) are found in a light tan colored, schistose matrix.