Cascade Canyon, San Gabriel Mts, San Bernardino Co., California, USA.
At least 20 minerals can be collected in the Cascade canyon area, among them lazurite, diopside, corundum, “hydrotroilite” and phlogopite. Lapis lazuli occurs in the limestone in small bands from 1/8 inch to six inches wide, sometimes containing pyrite crystals. Corundum has not been found in the canyon proper, but good specimens have been obtained in San Antonio wash. Crystals are from 1/4 inch to one inch in length and are of a pinkish color.
A large variety of metamorphic rocks occur here.
Check out this link for more info about the minerals and the location: http://rockingwiththerocks.com/cascade_canyon.html