Online Encyclopedia

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

PYROXENE

Online Encyclopedia

Originally appearing in Volume V22, Page 696 of the 1911 Encyclopedia Britannica.

» Make a correction to this article.
» Add information or comments to this article.

Encyclopedia Home :: PYR-RAY

Spread the word:

del.icio.us it!

PYROXENE , an important See also:

GROUP

group of See also:

rock-forming minerals, very similar in chemical See also:

composition and See also:

general characters to the amphiboles (q.v.). Although crystallizing in three different systems, they all possess distinct prismatic cleavages, the angles between which are about 87° (the cleavage See also:

ANGLE (from the Lat. angulus, a corner, a diminutive, of which the primitive form, angus, does not occur in Latin; cognate are the Lat. angere, to compress into a bend or to strangle, and the Gr. ayKOS, a bend; both connected with the Aryan root ank-, to

angle in the amphiboles being 56°). They are metasilicates, but, as shown in the following table, the composition varies widely in the different See also:

SPECIES

species, with corresponding See also:

DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences in the various See also:

PHYSICAL

physical characters. The name pyroxene was originally given by R. J. Haiiy in 1796 to the See also:

black crystals of See also:

AUGITE

augite found in the lavas of See also:

VESUVIUS (also Vesevus in ancient poets)

Vesuvius and See also:

Etna: he derived the name from the See also:

Greek a6p (See also:

FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire) and ivos (a stranger), because he thought that the crystals had been accidentally caught up by the lavas which contained them. As a See also:

MATTER

matter of fact, the pyroxenes are, next to the felspars, the commonest constituents of igneous rocks of almost all kinds, being especially characteristic of those of basic composition. An igneous rock composed almost wholly of pyroxene is known as a See also:

PYROXENITE

pyroxenite. Besides being minerals of See also:

PRIMARY

primary origin in igneous rocks, the pyroxenes are also of frequent occurrence in metamorphic rocks, for example, in crystalline limestones, being then of secondary origin. At the See also:

PRESENT

present See also:

day the name pyroxene is used as a group name for all the minerals enumerated below, though sometimes it is also applied as a specific name to include the See also:

MONOCLINIC

monoclinic members See also:

DIOPSIDE

diopside, hedenbergite, schefferite and augite. Orthorhombic See also:

SERIES (a Latin word from serere, to join)

Series. See also:

ENSTATITE

Enstatite MgSiOi.

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]
PYROPHYLLITE

[next]
PYROXENITE