Also found in: Dictionary, Wikipedia.


Any dike rock or salic lava that is characterized by the presence of albite or albite oligoclase, chlorite, epidote, and calcite.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



an effusive or vein magmatic rock with phenocrysts of alkali feldspar (predominantly albite) and colored minerals (usually biotite and sometimes diopside). The ground mass is compact and consists mainly of isometric or elongated microlites of albite. There are quartz keratophyres, orthoclase keratophyres, and so on (depending upon the light mineral present in them along with the albite). Keratophyres are usually genetically associated with spilites.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.