Those analyses have revealed traces of gold and iron, along with rarer minerals such as kamacite, schreibersite, taenite
, and troilite.
Traces of rare minerals have also been found, including taenite
, troilite, kamacite and schreibersite.
Occurrence: In "plessite," an intergrowth of taenite
and kamacite; other associated minerals are: nickelphosphide, schreibersite, awaruite and graphite.
Main iron-nickel minerals are kamacite and taenite. Minor minerals include schreibersite, rhabdite, troilite, cohenite, graphite, and sphalerite (Buchwald 1975; Dominik 1976).
Selected microprobe analysis of the Morasko meteorite and micrometeorites (in per cent) Meteorite Kamacite Taenite O Si S 0.02 0.01 Fe 95.42 80.49 Ni 6.49 18.08 Mg Al Mn Total 101.1 98.6 [Fe.sub.3][0.sub.4] Fe00H Micrometeorites with low Ni content Sample 3/11 Sample PS/40 O 1.35 0.005 Si 1.18 0.004 S 0.01 0.001 Fe 55.93 62.97 Ni 0.001 0.001 Mg Al Mn Total 58.47 * 62.98 * [Fe.sub.3][0.sub.4] 77.2 86.9 Fe00H 88.9 100.1 Micrometeorite with high Ni content Sample 4/KKH O 6.77 Si 0.64 S Fe 87.04 Ni 4.66 Mg 0.05 Al 0.57 Mn 0.27 Total 100.0 [Fe.sub.3][0.sub.4] Fe00H * OH and O bounded with Fe were not analysed
Opaque phases include troilite, taenite
, tetrataenite, kamacite, chromite and ilmenite.
The size and composition of grains of the iron-nickel mineral taenite are related to the rate at which they cooled from high temperatures.
However, meteorites rich in solar-wind-implanted gases (and thus presumably from asteroids' surfaces) contain taenite grains with widely varying cooling rates: some dropped only a few tenths of a degree per million years, others did so thousands of times faster.
Occurrence: Associated minerals are: kamacite, taenite
, troilite and forsterite.
Iron meteorites will show a distinct Widmanstatten pattern, the interplay of the nickel-iron alloys kamacite and taenite
, when a freshly polished interior surface is etched with dilute acid.