Mackinawite, Pentlandite, and Native Copper from the Newport Pallasite1

Peter R. Buseck
Departments of Geology and Chemistry, Arizona State University, Tempe, Arizona 85281
1Contribution No. 30 from the Center for Meteorite Studies, Arizona State University.

Summary: These minerals indicate strongly reducing conditions as well as extremely low sulphur fugacities within the Newport pallasite. They all formed at low temperatures (upper limit 580° C) and in the solid state. This is the first reported occurrence of mackinawite and pentlandite from a pallasitic meteorite; Cu is known from only one other pallasite. Microprobe analyses of a large Cu grain indicate its composition as 98·6 ± 0·5 %, Ni 2·0 ± 0·5, Fe below the limit of detection (∼0.3).

Mineralogical Magazine; March 1968 v. 36; no. 281; p. 717-725; DOI: 10.1180/minmag.1968.036.281.13
© 1968, The Mineralogical Society
Mineralogical Society (www.minersoc.org)