Eclogitic Pyroxenes, Ordered with P2 Symmetry
- 25 November 1966
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 154 (3752), 1003-1004
- https://doi.org/10.1126/science.154.3752.1003
Abstract
X-ray diffraction crystal-structure analysis of omphacite from eclogite, Tiburon Peninsula, Marin County, California, shows that this clinopyroxene has P2 symmetry with a nearly ordered distribution of the multiple cation content defined by its approximate formula: (Nao.5 Cao.5) (Mgo.4Fe2+ 0.1 Al0.4 Fe3 +0.1) Si206. Na+ and Ca2+ tend to assume alternate locations in the structure, and ( Mg,Fe2+) octahedra alternate with Al3+. or (Al,F3+) octahedra in chains along c.Keywords
This publication has 1 reference indexed in Scilit:
- Eclogites and Eclogites: Their Differences and SimilaritiesGSA Bulletin, 1965