Brachinite
{{short description|Group of meteorites}}
File:NWA 3151 meteorite, brachinite.jpg
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.
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.{{cite web|title=Brachina|url=http://www.lpi.usra.edu/meteor/metbull.php?sea=Brachinite&sfor=types&ants=&falls=&valids=&stype=exact&lrec=2000&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&snew=0&pnt=Normal%20table&code=5127|publisher=Meteoritical Society|access-date=21 November 2022}}
Description
Brachinites consist almost entirely of olivine (74 to 98% by volume). Other minerals include plagioclase (6.7 to 12.9%), iron sulfides (1.8 to 4.0%), clinopyroxene (1.5 to 8.2%) and orthopyroxene (0 to 2.4%). Trace minerals include phosphates and meteoritic iron. The only deviation from chondrites is the very high olivine/orthopyroxene ratio.{{cite journal|last=Nehru|first=C. E.|author2=M. Prinz |author3=M. K. Weisberg |author4=M. Ebihara |author5=R. N. Clayton |author6=T. K. Mayeda |title=Brachinites: A New Primitive Achondrite Group|journal=Meteoritics|year=1992|volume=27|issue=3|pages=267}}
Specimens
As of 2022, there were 56 meteorites classified as brachinites.{{cite web|title=Meteoritical Bulletin Database|url=http://www.lpi.usra.edu/meteor/metbull.php|publisher=Meteoritical Society|access-date=21 November 2022}} A notable example is the type specimen, the Brachina meteorite.