Brachinite

Brachinites are a group of meteorites that are classified either as primitive achondrites or as asteroidal achondrites. Like all primitive achondrites, they have similarities with chondrites and achondrites. Brachinites contain 74 to 98% (Volume) olivine.

Slice of the Northwest Africa 3151 meteorite.

Naming and history

Brachinites are named after the Brachina meteorite, the type specimen of this group which in turn is named after Brachina, South Australia.[1]

Description

Brachinites are almost entirely made from olivine (74-98 Volume-%). Other minerals include plagioclase (6.7 to 12.9%), iron sulfides (1.8 - 4.0%), clinopyroxene (1.5 - 8.2%) and orthopyroxene (0 - 2.4%). Trace minerals include phosphates and meteoric iron. The only deviation from chondrites is the very high olivine/orthopyroxene ratio.[2]

Specimen

There are currently 30 meteorites that are classified as brachinites.[3] A notable example is the type specimen, the Brachina meteorite.

See also

References
  1. "Brachina". Meteoritical Society. Retrieved 15 December 2012.
  2. Nehru, C. E.; M. Prinz; M. K. Weisberg; M. Ebihara; R. N. Clayton; T. K. Mayeda (1992). "Brachinites: A New Primitive Achondrite Group". Meteoritics. 27 (3): 267.
  3. "Meteoritical Bulletin Database". Meteoritical Society. Retrieved 20 December 2012.
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