Phosphoran Olivine from Pine Canyon, Piute Co., Utah

S. O. Agrell1, 3, N. R. Charnley2 and O. A. Chinner1
1 Dept of Earth Sciences, Downing Street, Cambridge CB2 3EQ, UK
2 Department of Earth Sciences, Oxford, OX1 3PR, UK
3 Died January 29, 1996

Abstract: Olivines containing up to 6.1 wt.% P2O5 occur in association with apatite and an unnamed NaCaMg phosphate phase. Phosphoran olivine has been recorded only in pallasite meteorites and from one other terrestrial occurrence. The rarity of palpable phosphorus substitution for silicon may be related to the fact that in most terrestrial rocks, phosphorus is incorporated initially, and remains as, apatite; thus phosphorus excess in an undersilicated environment must be uncommon. However the highly capricious distribution of phosphorus in individual olivines from this and the meteoritic occurences suggests disequilibrium, and questions whether phosphoran olivine is ever stable relative to combinations of P-free olivine and phosphate/phosphide minerals.

Keywords: phosphorus • olivine • apatite • Pine Canyon • Utah

Mineralogical Magazine; April 1998 v. 62; no. 2; p. 265-269; DOI: 10.1180/002646198547620
© 1998, The Mineralogical Society
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