There are extensive beds of salt under parts of New York, Michigan, Ohio, Oklahoma, Kansas, etc., which are mostly worked by drilling wells into the salt layer, then introducing hot water to dissolve the salt. The brine thus formed is pumped to the surface, and the salt recovered by evaporation in pans. During the process, skeleton crystals of salt with concave faces may form, but in Nature the crystals are uniformly solid cubes. Boracite Mg₇Cl₂B₁₆O₃₀ Occurs in small crystals or granular masses; hardness of crystals, 7; of the masses, 4.5; specific gravity 3; colorless to white; luster vitreous; transparent to translucent on thin edges. Small crystals, associated with salt and gypsum, occur in the beds and incrustations, which result from the drying up of alkaline lakes, especially in Nevada and southern California. The crystals are orthorhombic, but appear like perfect cubes, with the edges beveled and part of the corners cut. They are not easily dissolved in water, but quickly go into solution in hydrochloric acid. Colemanite Ca₂B₆O₁₁ + 5H₂O Occurs in crystals or compact masses; hardness, 4.5; specific gravity, 2.4; colorless to white; luster vitreous; translucent on thin edges. The crystals when they occur, are monoclinic; but usually colemanite is a bedded deposit, which has resulted from the drying up of a saline lake. It was first found in Death Valley, Cal., in 1882, then near Daggett, Cal., and since then in several similar locations in Nevada and Oregon. The deposits are of all grades of purity, the colemanite being mixed with varying quantities of mud. Today this mineral is the chief source of borax, which is used in medicines, cosmetics, colored glazes, enamel, and as a preservative. Borax NaB₄O₇ + 10H₂O Occurs in crystals or in powdery incrustations; hardness, 2; specific gravity, 1.7; colorless to white; luster vitreous; translucent on thin edges. The crystals are tiny and monoclinic, this mineral being usually obtained by the evaporation of the saline waters of such lakes as Clear and Borax Lakes in southern California, or from the muds of salt marshes, like Searles Borax Marsh in California. Originally most of our borax came from a large saline lake in Tibet, but now most of it is obtained from colemanite. Borax is soluble in water, giving it a sweetish taste. Sulphur S Pl. 51 Occurs in crystals, incrustations or compact masses; hardness, 2; specific gravity, 2; color yellow; streak yellow; luster resinous; translucent on thin edges.