23.—Copper.
Occurs in irregular masses; metallic lustre; can be cut with a knife; malleable; ductile; fusible; gravity 8.8.
Value.—A source of copper and silver.
Localities.—Most abundant in the trap and “freestone” regions. New Brunswick, Somerville, Schuyler’s and Flemington, N. J.; Whately, Mass.; Cornwall and Shannonville, Pa.; Polk County, Tenn.; Keweenaw Point, Lake Superior; Calaveras, Amador and Santa Barbara Counties, Cal.; on Gila River, Ariz.