Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

HARMOTOME

Online Encyclopedia
Originally appearing in Volume V13, Page 10 of the 1911 Encyclopedia Britannica.
» Make a correction to this article.
» Add information or comments to this article.
Spread the word: del.icio.us del.icio.us it!

HARMOTOME , a See also:

mineral of the zeolite See also:group, consisting of hydrous See also:barium and See also:aluminium silicate, H2BaAl2(SiO3)5+5H20. Usually a small amount of See also:potassium is See also:present replacing See also:part of the barium. The See also:system of See also:crystallization is See also:monoclinic; only complex twinned crystals are known. A See also:common and characteristic See also:form of twinned crystal, such as is represented in the figure, consists of four intercrossing individuals twinned together according to two twin-See also:laws; the See also:compound group resembles a tetragonal crystal with See also:prism and See also:pyramid, but may be distinguished from this by the grooves along the edges of the pseudo-prism. The faces of the crystals are marked by characteristic striations, as indicated in the figure. Twinned crystals of exactly the same See also:kind are also frequent in See also:phillipsite (q.v.). Crystals are usually See also:white and translucent, with a vitreous lustre. The hardness is 4zf and the specific gravity 2.5. The name harrnotome (from apµos, " a See also:joint," and TEµvely, " to cut ") was given by R. J. flatly in 1801, and has a crystallographic signification. Earlier names are See also:cross-See also:stone (Ger. Kreuzstein), ercinite, andreasbergolite and andreolite, the two last being derived from the locality, Andreasberg in the Harz.

Morvenite (from Morven in See also:

Argyllshire) is the name given to small transparent crystals formerly referred to phillipsite. Like other See also:zeolites, harmotome occurs with See also:calcite in the amygdaloidal cavities of volcanic rocks, for example, in the dolerites of See also:Dumbartonshire, and as See also:fine crystals in the See also:agate-lined cavities in the melaphyre of See also:Oberstein in See also:Germany. It also occurs in See also:gneiss, and sometimes in metalliferous See also:veins. At Andreasberg in the Harz it is found in the See also:lead and See also:silver veins; and at Strontian in Argyllshire in lead veins, associated with brewsterite (a See also:strontium and barium zeolite), See also:barytes and calcite. (L. J.

End of Article: HARMOTOME

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to 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.

[back]
HARMONY (Gr. dpµovia, a concord of musical sounds,... 		[next]
HARMS, CLAUS (1778-1855)

Site © 2006 - Net Industries