Occurs in irregular beds or masses; brittle; saline taste; crackles in the fire. LOCALITIES.--Found with _gypsum_, clay and sandstone. Washington County, Va.; Petit Anse, La.; Silver Peak, Nev.; Salmon River Mountains, Oregon. 59.--RUTILE. Occurs in crystals generally; metallic lustre; powder pale brown; brittle; unchanged by heat or acids; if powdered and fused with potash, then dissolved in muriatic acid, the solution boiled with tinfoil assumes a beautiful violet color; gravity 4. VALUE.--Used for coloring porcelain and artificial teeth. LOCALITIES.--Found in granite and, limestone rocks. Warren, Me.; Merrimack, and Warren, N. H.; Bristol, Putney and Waterbury, Vt.; Windsor, Shelburne, Barre, Conway and Leyden, Mass.; Monroe, Conn.; Warwick, Edenville, Amity and Kingsbridge, N. Y.; Sudsbury, West Bradford, Parksburg, Concord and Newlin, Pa.; Newton, N. J.; Crowder’s and Clubb Mountains, N. C.; Habersham and Lincoln Counties, Ga.; Magnet Cave, Ark. 60.--SERPENTINE. Occurs in masses; feeble, resinous lustre; color oily green; powder whitish; often yellowish gray on the outside; can be cut easily; takes a fine polish; becomes reddish by heat; gravity 2.5--same as _Marble_. VALUE.--Worked into mantels, jambs, table-tops, and many other ornaments. LOCALITIES.--Found as a rock in large masses. Deer Isle, Me.; Baltimore, Cavendish, Jay and Troy, Vt.; Newbury, Blanford, Middlefield and Westfield, Mass.; Newport, R. I.; near New Haven and Milford, Conn.; Port Henry, Antwerp, Syracuse, Warwick, Phillipstown, Canton, Gouverneur, Johnsburg, Davenport’s Neck, New Rochelle and Rye, N. Y.; Frankford, Hoboken and Montville, N. J.; Texas, Pa.; Cooptown, Md.; Patterson, N. C.; Calaveras County, Cal.; Alder Gulch, Mont. Marble veined with serpentine is called _verd-antique_. 61.--SILICATE OF COPPER. Occurs in incrustations and masses; color bluish-green; not fibrous; surface smooth; easily cut; does not effervesce in acid; blackens by heat; gravity 2. VALUE.--An ore of copper, yielding thirty per cent. LOCALITIES.--Found with other copper ores. Somerville and Schuyler’s, N. J.; Morgantown and Cornwall, Pa.; Wolcottville, Conn.; Big Williams’ Fork, Ariz. 62.--SILVER. Occurs in masses, or strings and threads penetrating rocks and native copper and galena; metallic lustre; tarnishes grayish black; can be cut in slices and hammered out; dissolved in muriatic acid, it turns black on exposure; gravity 10. LOCALITIES.--Chiefly found with copper near trap-rocks, and in fine grained _galena_ and dark brown _blende_. _Gold_ contains from one to fifteen per cent. Bridgewater, N. J.; Davidson and Stanley Counties, N. C.; Lake Superior Region; Poorman’s Lode, Idaho; Comstock Lode and Montezuma Ledge, Nev.; Alpine County and Maris Vein, Cal.; Clear Creek County, Col. 63.--SILVER GLANCE. Occurs in small lumps, plates and threads; color dark gray; cuts like lead; melts in a candle giving off sulphur fumes; gravity 7.