LOCALITIES.--Found in _Serpentine_. Bare Hills, Cooptown and north part of Cecil County, Md.; Nottingham, W. Goshen, Williston, Fulton, Mineral Hill, Texas and Unionville, Pa.; Jay, New Fane, Westfield and Troy, Vt.; Chester and Blanford, Mass.; Loudon County, Va.; Yancy County, N. C.; North Almaden, New Idria and Coloma, Cal. 21.--CINNABAR. Occurs in granular or earthy masses; resembles iron-rust, but is a yellowish-red; powder scarlet; easily cut with a knife; thrown on red-hot iron, evaporates, giving off odor of sulphur; rubbed on copper, “silvers” it; gravity 9, or about as heavy as _Copper_. VALUE.--The source of mercury (containing eighty-four per cent.) and vermilion. LOCALITIES.--Found in slate and limestone rocks. Centreville, Coulterville, New Idria and New Almaden, and Lake and San Luis Obispo Counties, California; Idaho. 22.--COBALT PYRITES. Occurs crystallized and massive; does not scratch glass easily; metallic lustre; tarnish, copper-red; powder, blackish-gray; brittle; heated on charcoal gives off sulphur fumes; heated with borax gives a blue glass; gravity 5. VALUE.--An ore of cobalt, yielding twenty per cent. LOCALITIES.--Usually found in slate or granite rocks with _Copper Pyrites_. Mineral Hill, Md.; Mine-la-Motte, Mo. 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. 24.--COPPER GLANCE. Occurs crystallized and massive; color, blackish lead-gray, often tarnished blue or green; nearly as hard as marble; brittle; a splinter will melt in a candle, giving off the odor of sulphur; dissolved in nitric acid, it will coat a knife-blade with copper; metallic lustre; gravity 5.5. VALUE.--An ore of copper, yielding seventy-five per cent. LOCALITIES.--Found at copper-mines. Simsbury, Bristol and Cheshire, Conn.; Schuyler’s Mines, N. J.; Orange County, Va.; near Newmarket, Md.; Lake Superior copper-region; La Paz, Arizona; Washoe, Humboldt, Nye and Churchill Counties, Nev. 25.--COPPER NICKEL. Occurs in masses; metallic lustre; color pale copper-red; tarnishes gray to black; powder pale brownish-black; brittle; on charcoal melts giving the odor of garlic; becomes green in nitric acid; gravity 7.5. VALUE.--An ore of nickel (containing forty-four per cent.) and arsenic. LOCALITIES.--Found in granite regions. Chatham, Conn. 26.--COPPER PYRITES. Occurs in crystals and masses; color brass-yellow; tarnishes green; metallic lustre when freshly broken; can be cut with a knife; brittle; powder greenish black; on charcoal melts giving off sulphur fumes; dissolves in nitric acid, making a green liquid; gravity 4.2.