An Etymological Dictionary of Astronomy and Astrophysics
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A class of → stony meteorites that lack → chondrules. They are made of rock that has crystallized from a molten state. Achondrites are relatively rare, accounting for about 8% of all meteorite falls.

Achondrite, from Gk. prefix a- (an- before stems beginning with a vowel or h) "not, without, lacking" + Gk. chondrite, from chondr-, from chondros "grain," + affix -ite.

A rare type of → stony meteorite having a higher → carbon content than other classes of meteorite. They represent only ~5% of the known meteorites. Their bulk composition is mainly → silicates, → oxides and sulfides, whilst the minerals → olivine and serpentine are characteristic. The six classes of carbonaceous chondrites are: → CI chondrites, CM chondrites, CV chondrites, CO chondrites, CK chondrites, CR chondrites, CH chondrites, and CB chondrites.

→ carbonaceous; → chondrite.

The most common type of → meteorites containing → chondrules. These → stony meteorites make up about 86% of all meteorites. An important feature of the chondrites is that, with the exception of a few highly → volatile elements, they have the same composition as the Sun.

Chondrite, from chondr-, from chondros "grain", + suffix → -ite.

A group of very rare → carbonaceous chondrites which are unusual because they do not have → chondrules. They are thought to be the most primitive of all meteorites. As a result of alteration, they lack chondrules and → CAIs, but contain up to 20% water, as well as various alteration minerals. Only five CI chondrite falls are known, and of these, only four are massive enough for multiple chemical analyses. The Orgueil meteorite is the most massive of CI chondrites.

C for → carbon, I stands for Ivuna meteorite that fell in Tanzania in 1938; → chondrite.

Same as → enstatite chondrite.

→ enstatite; → type; → chondrite.

A rare kind of → meteorite containing the → enstatite mineral. These meteorites are thought to comprise only about 2% of the chondrites that fall on Earth. Also called → E-type chondrite.

→ enstatite; → chondrite.