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VESUVIANITE , a See also: rock-forming See also:mineral of complex com-
position. It is a basic See also:calcium and See also:aluminium silicate See also:con-
aining small amounts of See also:iron, See also:magnesium, See also:water,
See also:fluorine, etc., and sometimes See also:boron; the ap-
proximate See also:formula is H2Ca6(Al,Fe)aSi5O18. It
crystallizes in the tetragonal See also:system, but often
exhibits See also:optical anomalies, and the optical sign
varies from See also:positive to negative. Well-devel-
oped crystals are of frequent occurrence. They
usually have the See also:form of four- or eight-sided
prisms terminated by the basal planes (c) and
See also:pyramid-planes (p in fig.); the See also:prism-planes are vertically
striated and the basal planes smooth and See also:bright. Crystals are
transparent to translucent, vitreous in lustre and vary in See also:colour from See also:- BROWN
- BROWN, CHARLES BROCKDEN (1771-181o)
- BROWN, FORD MADOX (1821-1893)
- BROWN, FRANCIS (1849- )
- BROWN, GEORGE (1818-188o)
- BROWN, HENRY KIRKE (1814-1886)
- BROWN, JACOB (1775–1828)
- BROWN, JOHN (1715–1766)
- BROWN, JOHN (1722-1787)
- BROWN, JOHN (1735–1788)
- BROWN, JOHN (1784–1858)
- BROWN, JOHN (1800-1859)
- BROWN, JOHN (1810—1882)
- BROWN, JOHN GEORGE (1831— )
- BROWN, ROBERT (1773-1858)
- BROWN, SAMUEL MORISON (1817—1856)
- BROWN, SIR GEORGE (1790-1865)
- BROWN, SIR JOHN (1816-1896)
- BROWN, SIR WILLIAM, BART
- BROWN, THOMAS (1663-1704)
- BROWN, THOMAS (1778-1820)
- BROWN, THOMAS EDWARD (1830-1897)
- BROWN, WILLIAM LAURENCE (1755–1830)
brown to See also:green; a See also:sky-See also:blue variety, called cyprine, owes its colour to the presence of a trace of See also:copper. The specific gravity is 3.4 and the hardness 62. The name vesuvianite was given by A. G. See also:Werner in 1795, because See also:fine crystals of the mineral are found at See also:Vesuvius; these are brown in colour and occur in the ejected See also:limestone blocks of See also:Monte Somma. Several other names have been applied to this See also:species, one of which, idocrase of R. J. See also: Hauy (1796), is now in See also:common use.
Vesuvianite is typically a mineral of contact-metamorphic origin, occurring most frequently in crystalline limestones at their contact with igneous rock-masses; it also occurs in See also:serpentine, See also:chlorite-schist and See also:gneiss, and is usually associated with See also:garnet, See also:diopside, See also:wollastonite, &c. Localities which have yielded fine crystallized specimens are the See also:Ala valley near See also:Turin, See also:Piedmont, Monte Somma (Vesuvius), Monzoni in the Fassa valley, See also:Tirol, Achmatovsk near Zlatonst in the Urals, the See also:River Wilui See also:district near See also:Lake See also:Baikal in See also:Siberia (" wiluite "), See also:Christiansand in See also:Norway, &c. When found in transparent crystals of a See also:good green or brown colour it is occasionally cut as a See also:gem-See also:- STONE
- STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
- STONE, CHARLES POMEROY (1824-1887)
- STONE, EDWARD JAMES (1831-1897)
- STONE, FRANK (1800-1859)
- STONE, GEORGE (1708—1764)
- STONE, LUCY [BLACKWELL] (1818-1893)
- STONE, MARCUS (184o— )
- STONE, NICHOLAS (1586-1647)
stone. A compact variety, closely resembling See also:jade in See also:appearance, has been used as an ornamental stone. (L. J.
End of Article: VESUVIANITE
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