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WITHERITE , a See also:mineral consisting of See also:barium carbonate (BaCO3), crystallizing in the orthorhombic See also:system. The crystals are invariably twinned together in See also:groups of three, giving rise to pseudo-hexagonal forms somewhat resembling See also:bipyramidal crystals of See also:quartz, the faces are usually rough and striated horizontally. The See also:colour is dull See also:- WHITE
- WHITE, ANDREW DICKSON (1832– )
- WHITE, GILBERT (1720–1793)
- WHITE, HENRY KIRKE (1785-1806)
- WHITE, HUGH LAWSON (1773-1840)
- WHITE, JOSEPH BLANCO (1775-1841)
- WHITE, RICHARD GRANT (1822-1885)
- WHITE, ROBERT (1645-1704)
- WHITE, SIR GEORGE STUART (1835– )
- WHITE, SIR THOMAS (1492-1567)
- WHITE, SIR WILLIAM ARTHUR (1824--1891)
- WHITE, SIR WILLIAM HENRY (1845– )
- WHITE, THOMAS (1628-1698)
- WHITE, THOMAS (c. 1550-1624)
white or sometimes greyish, the hardness is 32 and the specific gravity 4.3. The mineral is named after W. Withering, who in 1784 recognized it to be chemically distinct from See also:barytes. It occurs in See also:veins of See also:lead ore at See also:Hexham in See also:Northumberland, See also:Alston in See also:Cumberland, Anglezark, near See also:Chorley in See also:Lancashire, and a few other localities. Witherite is readily altered to barium sulphate by the See also:action of See also:water containing See also:calcium sulphate in See also:solution, and crystals are therefore frequently encrusted with barytes. It is the See also:chief source of barium salts, and is See also:mined in considerable amounts in Northumberland. It is used for the preparation of See also:rat See also:poison, in the manufacture of See also:glass and See also:porcelain, and formerly for refining See also:sugar. (L. J.
End of Article: WITHERITE
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