Krinovite
A green sodium chromium silicate found only in the graphite nodules of iron meteorites.
Key facts
- Formula
- NaMg2CrSi3O10
- Family
- Silicates
- Crystal system
- Triclinic
- First described
- graphite nodules in iron meteorites, 1968
Krinovite was first described in 1968 from graphite nodules in the iron meteorites Canyon Diablo, Wichita County and Youndegin. It is named after Evgeny Krinov, the Russian scientist who studied the Sikhote-Alin fall. It is still known only from meteorites.
What it is
Krinovite is a chain silicate containing sodium, magnesium and chromium. Chromium gives it an emerald-green colour.
Where it is found
It occurs with kosmochlor, chromite and other unusual minerals in rounded nodules of graphite and troilite in IAB iron meteorites. These nodules preserve minerals that formed under very low oxygen in the parent body.
How it is recognised
It forms tiny bright green grains, visible under a microscope in polished slices of graphite nodules, and is confirmed by its chemistry.
Did you know?
Evgeny Krinov led expeditions to recover the Sikhote-Alin iron meteorites after the 1947 fall.
Krinovite has never been found in any rock from Earth.