|
COLEMANITE , a hydrous See also:calcium borate, Ca2B6O11+5H2O, found in See also:California as brilliant ,See also:monoclinic crystals. It contains 50.9% of See also:boron trioxide, and is an important source of commercial borates and boracic See also:acid. Beautifully See also:developed crystals, up to 2 or 3 in. in length, encrust cavities in compact, 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 colemanite; they are colourless and transparent, and the brilliant lustre of their faces is vitreous to adamantine in See also:character. There is a perfect cleavage parallel to the See also:plane of symmetry of the crystals. Hardness 4-4i; specific gravity 2.42. The See also:mineral was first discovered in 1882 in See also:Death Valley, Inyo See also:county, California, and in the following See also:year it was found in greater abundance near Daggett in See also:San Bernardino county, forming with other borates and borosilicates a See also:bed in sedimentary strata of sandstones and See also:clays; in more See also:recent years very large masses have been found and worked in these localities, and also in Los Angeles county (see See also:Special See also:Report, 1905, of U.S. See also:Census See also:Bureau on Mines and Quarries; and Mineral Resources of the U.S., 1907). .
Priceite and pandermite are hydrous calcium borates with very nearly the same See also:composition as colemanite, and they may really be only impure forms of this See also:species. They are massive white minerals, the former friable and See also:chalk-like, and the latter See also:firm and compact in texture. Priceite occurs near Chetco in See also:Curry county, See also:Oregon, where it forms layers between a bed of See also:slate and one of tough See also:blue steatite; embedded in the steatite are rounded masses of priceite varying in See also:size from that of a See also:pea to masses weighing 2001b. Pandermite comes from See also:Asia See also:Minor, and is shipped from the See also:port of See also:Panderma on the See also:Sea of See also:Marmora: it occurs as large nodules, up to a ton in See also:weight, beneath a thick bed of See also:gypsum.
Another borate of commercial importance found abundantly in the Californian deposits is ulexite, also known as boronatrocalcite or " See also:cotton-See also:ball," a hydrous calcium and See also:sodium borate, CaNaB5O9+8H20, which forms rounded masses consisting of a loose aggregate of See also:fine See also:fibres. It is the See also:principal species in the borate deposits in the See also:Atacama region of See also:South See also:America. (L. J.
End of Article: COLEMANITE
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!