amphoteriteとは 意味・読み方・使い方

Amphoterite is an obsolete term used to describe chondritic meteorites that are now classified as LL (Low Iron and Low total metal content) types. Most of the iron in these types of meteorites is present as ironoxide in the minerals (e.g. olivine) rather than as free metal, as it is found in most other meteorites. Free metallic iron amounts to between 0.3% and 3.0% of the meteorite, and with a total iron content of 20% give or take a couple of percentage points. There will be a number after the LL in a meteorites classification type, e.g. LL3, LL5, LL6. (Types range from 3 to 7) The number indicates the amount of alteration suffered by the chondrules in the meteorite. A chondrule is a small mineral ball generally 0.1 mm to 4 mm in diameter. An LL3 type is pristine with perfectly discernible chondrules, an LL7 type has been melted or altered by pressure or other force to almost completely obliterate the round chondrules.