Ophit
Ophite (from Greek ὄφις óphis "snake", after the similarity of the structure with the back drawing of some snakes) is a dark green, granular to dense rock made of plagioclase and pseudomorphic amphibole (so-called uralitic hornblende ) with light augite , primary hornblende, titanium iron and sometimes diallag , outwardly it resembles serpentine . On the fissures it is sometimes covered with yellow-green epidote and iron sheen . It can be found, for example, in the Pyrenees , where it forms individual peaks , or in Spain and Portugal , mostly accompanied by gray and brick-red plaster , iron-shed, colored clays and purple, red, green or gray marls .
The ophitic structure is also named after the drawing on the back of some snakes , in which plate or strip-shaped plagioclase crystals lie in an irregular, often confused arrangement in a matrix of other minerals. An example of a rock with such a structure is the dolerite , in which some varieties lead in a matrix of large Augite ridge-shaped plagioclase.
Individual evidence
- ↑ Girth, Eike et al. (1977): Lexicon for mineral and rock lovers . CJ Bucher AG, Lucerne / Frankfurt, p. 256, ISBN 3-7658-0253-0
- ↑ Uralit in the Mineralienatlas Lexikon
- ^ Ophit in Meyers Konversationslexikon Vol. 12, 4th edition from 1885 to 1892 digitized edition
- ^ Hans Murawski, Wilhelm Meyer: Geological dictionary . 11th edition. Elsevier / Spektrum, Heidelberg 2004, ISBN 3-8274-1445-8 , pp. 262 .