31.—Galena.

Occurs in crystals and masses; brilliant lustre; brittle; easily broken; powder, when finely rubbed is black; can be cut with a knife; heated it gives off sulphur and melts; dissolves in nitric acid leaving a white powder at the bottom; gravity 7.5—or a little heavier than cast-iron.

Value.—The main source of lead (yielding eighty per cent), and also smelted for the silver it contains. Used also in glazing stone-ware.

Localities.—Generally found in limestone with Iron Pyrites, zinc-ore, etc. That found in slate is richest in silver. Abounds in Missouri, Illinois, Iowa, Wisconsin and Arkansas; Rossie, Wurtzboro, Ancram, Macomb and Ellenville, N. Y.; Lubec, Blue Hill Bay, Bingham and Parsonsville, Me.; Eaton, Shelburne, Haverill, Warren and Bath, N. H.; Thetford, Vt.; Southampton, Leverett and Sterling, Mass.; Middletown and Roxbury, Conn.; Phœnixville, Charlestown, Schuylkill, Pequea Valley and Shannonville, Pa.; Austin’s and Walton’s Mines, Va.; Cabarras County, N. C.; Brown’s Creek and Haysboro, Tenn.; Chocolate River, Mich.; Ingo County, Cal.; on Walker’s River and Steamboat Springs, Nev.; Castle Dome and Eureka, Ariz.; Clear Creek County, Col.; Virginia City and Red Bluff Lode, Mont.; Cache Valley, Utah.