|
CHRYSOBERYL , a yellow or See also:green 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, remarkable for its hardness, being exceeded in this respect only by the See also:diamond and See also:corundum. The name suggests that it was formerly regarded as a See also:golden variety of See also:beryl; and it is notable that though differing widely from beryl it yet bears some relationship to it inasmuch as it contains the See also:element See also:beryllium. In chrysoberyl, however, the beryllium exists as an aluminate, having the See also:formula BeAl2O4, or BeO•Al2O3. The See also:analysis of a specimen of Brazilian chrysoberyl gave alumina 78•Io, beryllia 17.94, and ferric See also:oxide 4.88%. The typical yellow See also:colour of the stone inclines in many cases to See also:pale green, occasionally passing into shades of dark green and 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. The See also:iron usually See also:present in the See also:mineral seems responsible for the green colour. Chrysoberyl is often mistaken by its colour for See also:chrysolite (q.v.), and has indeed been termed See also:Oriental chrysolite. In its crystalline forms it bears some relationship to chrysolite, both crystallizing in the orthorhombic See also:system, but it is a much harder and a denser mineral. As the two stones are See also:apt to be confounded, it may be convenient to contrast their See also:chief characters:
Chrysoberyl. Chrysolite.
Hardness . . . 8.5 6.5 to 7
Specific Gravity . 3.65 to 3.75 3.34 to 3.37
Chemical See also:Composition . . BeAl2Oa. Mg2SiO4.
Chrysoberyl is not infrequently cloudy, opalescent and chatoyant, and is then known as " cymophane " (Gr. agaa, a " See also:cloud "). The cloudiness is referable to the presence of multitudes of microscopic cavities. Some of the cymophane, when cut with a See also:convex See also:surface, forms the most valuable See also:kind of See also:cat's-See also:eye (see CAT'S-EYE). A remarkable dichroic variety of chrysoberyl is known as See also:alexandrite (q.v.).
Most chrysoberyl comes from See also:Brazil, chiefly from the See also:district of See also:Minas Novas in the See also:state of Minas Geraes, where it occurs as small See also:water-worn pebbles. The cymophane is mostly from the gem-gravels of See also:Ceylon. Chrysoberyl is known as a constituent of certain kinds of See also:granite, See also:pegmatite and See also:gneiss. In the See also:United States it occurs at Haddam, See also:Conn.; See also:Greenfield Centre, near See also:Saratoga Springs, N.Y.; and in Manhattan See also:island. It is known also in the See also:province of See also:Quebec, See also:Canada, and has been found near
Gwelo in See also:Rhodesia. (F. W.
End of Article: CHRYSOBERYL
Additional information and Comments
There are no comments yet for this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.
Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.
Links to articles and home page are always encouraged.
|
del.icio.us it!