Kosmochlor
Kosmochlor is a bright green sodium-chromium pyroxene first discovered in iron meteorites.
Kosmochlor is a pyroxene made of sodium, chromium, silicon and oxygen, NaCrSi2O6. Its name means 'cosmic green', after its vivid emerald colour, and it was first identified in iron meteorites, including Toluca from Mexico. It was once also called ureyite, after the chemist Harold Urey.
In iron meteorites, kosmochlor occurs as tiny grains in silicate and sulfide inclusions. It has since been found on Earth too, notably in jadeite rocks from Myanmar, where it adds green colour to some jade.
The mineral is interesting because chromium is usually locked up in chromite. Kosmochlor forms where sodium and silicon were available and oxygen levels were just right, so it helps researchers understand the chemistry of inclusions trapped in cooling metal. It is a good example of a mineral discovered in space rocks first and only later recognised in Earth's rocks.
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