SCHEELITE
This article appears in Volume V24, Page 315 of the Encyclopedia Britannica.
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Encyclopedia Britannica - Main :: SAR-SCY
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SCHEELITE , a mineral consisting of calcium tungstate, CaWO4. It was early known as " tungsten " (meaning in Swedish, " heavy stone "), and is the mineral in which K. W. Scheele discovered tungstic acid, hence the name scheelite. Well-developed crystals are not infrequent; they usually have the form of acute tetragonal bipyramids (P in fig.); sometimes other pyramid-faces are present, and these (g and n) being developed on only one side of P indicate the parallel-faced hemihedrism of the crystals. Compact and granular masses also occur. The colour is usually yellowish white See Also: - WHITE
- WHITE, ANDREW DICKSON (1832– )
- WHITE,
GILBERT See Also: - GILBERT
- GILBERT (KINGSMILL) ISLANDS
- GILBERT (or GYLBERDE), WILLIAM (1544-1603)
- GILBERT, ALFRED (1854– )
- GILBERT, ANN (1821-1904)
- GILBERT, GROVE KARL (1843– )
- GILBERT, J
- GILBERT, JOHN (1810-1889)
- GILBERT, MARIE DOLORES ELIZA ROSANNA [" LOLA MONTEZ "] (1818-1861)
- GILBERT, NICOLAS JOSEPH LAURENT (1751–1780)
- GILBERT, SIR HUMPHREY (c. 1539-1583)
- GILBERT, SIR JOSEPH HENRY (1817-1901)
- GILBERT, SIR WILLIAM SCHWENK (1836– )
(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)
or brownish, the crystals sometimes transparent to translucent; the lustre vitreous to adamantine. The hardness is 41, the specific gravity 6o. Molybdenum " is usually present, replacing an equivalent amount of tungsten; and in a green variety known as " cupro-scheelite " part of the calcium is replaced by copper.
Scheelite usually occurs with topaz , fluor, apatite, wolframite, &c., in tin-
bearing veins; and is sometimes found in association with gold. Fine crystals have been obtained from
Caldbeck Fells in Cumberland , Zinnwald and Elbogen in Bohemia, Guttannen in Switzerland, the Riesengebirge in Siltsia, Dragoon Mountains inArizona and elsewhere. At Trumbull in Connecticut and Kimpu-san in Japan large crystals of scheelite completely
altered to wolframite have been found: those from Japan have been called " reinite."
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