Online Encyclopedia

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

PEROVSKITE, or PEROFSKITE

Online Encyclopedia
Originally appearing in Volume V21, Page 179 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!

See also:

PEROVSKITE, or PEROFSKITE , a See also:mineral consisting of See also:calcium titanate, CaTiO3, usually with a small proportion of the calcium replaced by See also:iron. The crystals found in schistose rocks have the See also:form of cubes, which are sometimes modified on the edges and corners by numerous small planes; on the other See also:hand, the crystals occurring as an See also:accessory constituent of eruptive rocks are octahedral in form and microscopic in See also:size. Although geometrically cubic, the crystals 'are always doubly refracting, and they sometimes show See also:evidence of complex mimetic twinning; their structure as shown in polarized See also:light is very similar to that of the mineral See also:boracite, and they are therefore described as pseudo-cubic. There are distinct cleavages parallel to the faces of the See also:cube. The See also:colour varies from See also:pale yellow to blackish-See also:brown and the lustre is adamantine to metallic; the crystals are transparent to opaque. The See also:index of See also:refraction is high, the hardness 5z and the specific gravity 4.0. The mineral was discovered at Achmatovsk near Zlatonst in the Urals by G. See also:Rose in 1839, and named in See also:honour of See also:Count L. A. Perovsky;at this locality large cubes occur with See also:calcite and See also:magnetite in a See also:chlorite-schist. Similar crystals are also found in See also:talc-schist at See also:Zermatt in See also:Switzerland. The microscopic octahedral crystals are characteristic of melilite See also:basalt and See also:nepheline basalt; they have also been found in See also:peridotite and See also:serpentine.

(L. J.

End of Article: PEROVSKITE, or PEROFSKITE

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]
PERNE, ANDREW (c. 1519-1589) 		[next]
PEROWNE, JOHN JAMES STEWART (1823—1904)

Site © 2006 - Net Industries