GYPSUM. Shih-kau, Si-li-shih, of the Chinese, is a native sulphate of lime. It occurs as selen ite, plaster - of - paris, alabaster or snowy gyp sum, radiated gypsum, and satin spar or fibrous gypsum. Extensive beds of crystalline and fibrous gypsum and selenite occur near Ennore, the Red Hills, Ootatoor, Nellore, Tiagur, Madura, Banga lore, Sadras, Masulipatam, Hyderabad, and other localities. It can be purchased in most bazars in India under the name of Kulnar and Karpoora silasit, and is used in small doses as a medicine ; but the natives do not appear to be acquainted with its use in taking casts, plastering, and house decoration, or in manufacturing Keene's cement. It occurs very ab undantly in the Madras Presidency, in the form of fibrous and crystalline gypsums, both free from carbonate of lime, and well suited for the manufacture of plaster-of-paris for moulds, busts, statues, or ornaments.
Gypsum of gre,at purity was described by Dr. Jameson as occurring at Jalalpur, recommended for public buildings and ornamental works. In the western parts of Marwar are extensive rocks of earthy and granular sulphate of lime. Selenite occurs in various places in Kattyawar, and at Dholgaon in the Rajpipla country. Granular gyp stun. is found near the banks of the Tenasserim, in about lat. 13- 40' N. A fine variety of fibrous gyp mum (Sha-koung, Crux.) is brought to Burma from China. They use it in medicine, and say it is very cooling. This occurs in China, in the districts of Ilu-peit and Yun-yang-fu, Sze-chuen, Yun-nan, and Shan-tung. Gypsum is brought to Canton in abundance from tho N.W. of the province, and is ground into powder in mills. It is not used as manure by the Chinese, but is mixed with oil to form a cement for paying boats after they havebeen caulked. The powder is employed as a dentifrice, a cosmetic, and a, medicine, and sometimes also is boiled to make a gruel in fevers, under the idea that it is cooling. Its employment in colouring tea awl adulterating the Ping-fa, or powder sugar, is attributable to other motives than a wish to injnre the consumers.
Gypsum is named from earth, and 14/ffip, to concoct, i.e. formed or concocted in the earth. The better sorts of Derbyshire gypsum are employed in the Staffordshire potteries, as an ingredient in certain kinds of earthenware and porcelain, and also in making moulds for such articles of pottery as cannot be shaped on the common wheel. The finest pieces of this gypsum are reserved for orna mental purposes, such FIS vases, small statues, etc., of which a considerable manufacture exists in Derby. Gypsum in this form generally bears the name of alabaster ; gypsum, when calcined and reduced to powder, can be brought to a pulpy num by achnixture with water, and is the well known plaster-of-paris. Thia mass very soon sets, or returns to the solid form, giving out, while in the act of doing so, a considerable degree of he.at. Advantage is taken of this in the use of gypsum as a material for casting and taking impressions.
A white granular gypsum, suited for sculpture, occurs in the Jummoo territory, and an alabaster from Spiti is a hard white granular gypsum. Gypsum occurs in the marl beds of the Devonian or primary strata of the Salt Range. In the gypsum of Mari, Kalabagh, and Sardi, beautiful regular quartz crystals oceur, called Kalabagh and Mari diamonds. They are transpuent, milky, or red. The Bohemian topaz of the Jhdum consist of small crystals of this quartz, in the form of dodeca hedra, or double six-sided pyramids, but there is not the six-sided prism so characteristic of quartz. The Kalabagh diamonds are quartz in six-sided prisms, terminated by six-sided pyramids.
An inferior alabaster occurs at Sardi and on Karuli mountain, moneously called marble. Lahore gypsum is called Sang-i-jarahat, also Go danti ; that of the Jhelum and Rawnl Pindi is called Surma safed, a natue usually applied to the carbonate of lime Makol.—Powell's Handb.; Mad. Ex., 1857, Jur. Rep.; Simmonds; Tomlinson; Mason; Willicuns' Middle Kingdom; Snail+.