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Formula: (Ni,Fe)8(Si,P)3
Silicide-phosphide of nickel and iron
Crystal system: Trigonal
Environments
Perryite occurs in anomalously silicon-rich
mesosiderite meteorites and
enstatite chondrite meteorites, probably formed by
exsolution from kamacite
(HOM).
Localities
Mount Egerton meteorite, Upper Gascoyne Shire, Western Australia, Australia.
Perryite is a minor but regular constituent of the metal phase in
enstatite chondrite (aubrite) and
enstatite chondrite meteorites. Associated minerals include
kamacite and schreibersite.
Enstatitic meteorites represent the early stages of nebular
accretion.
A few fragments of the Egerton meteorite were collected in 1941 along the headstream of the Gascoine River. The
larger pieces of the meteorite (up to 77 g) were
predominantly composed of centimetre-sized enstatite crystals, whereas
the smaller ones comprised Fe–Ni metal enriched in silicon. The meteorite is classified as an anomalous aubrite
(enstatite achondrite). Its specific feature is a lack of
brecciation of enstatite
fragments typical for the majority of
aubrites. The unusual structure of its metal appears to be
due to a network of perryite lamellae
(Journal of Geosciences 66.4.189-198).
Perryite from the Egerton meteorite -
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The Kota-Kota meteorite, Nkhotakota, Central Region, Malawi, is an
enstatite chondrite. In addition to the common opaque
minerals troilite, kamacite and
schreibersite, the meteorite contains perryite, comprising an
estimated 10% to 15% of its opaque content. The perryite is typically intergrown with
troilite. The kamacite in
Kota-Kota was found to contain 2.6% Si and 3.0% Ni. This is a much lower Ni content than that of
kamacite in other
enstatite chondrites so far investigated, and is probably
related to the unusually high abundance of perryite here
(Mineralogical Magazine and Journal of the Mineralogical Society 36.850-854).
The South Oman meteorite, Al Wusta Governorate, Oman, is an
enstatite chondrite that contains perryite, but its
abundance is much less than in Kota-Kota. In the South Oman meteorite, perryite occurs as small laths,
usually associated with kamacite that contains 3.9% Si and 6.7% Ni. This
Si content is the highest yet observed in kamacite in
enstatite chondrites; the Ni content is normal
(Mineralogical Magazine and Journal of the Mineralogical Society 36.850-854).
The type locality, the Horse Creek meteorite, Baca County, Colorado, USA, is an
iron meteorite consisting mainly of
kamacite, with numerous thin, oriented lamellae of perryite
(Mineralogical Magazine and Journal of the Mineralogical Society 36.850-854).
Associated minerals include kamacite,
troilite and schreibersite
(HOM).
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