Roedderite
A rare sodium–potassium magnesium silicate of the osumilite group, first found in an enstatite chondrite.
Key facts
- Formula
- (Na,K)2(Mg,Fe)5Si12O30
- Family
- Silicates
- Crystal system
- Hexagonal
- First described
- the Indarch enstatite chondrite, 1966
Roedderite was first described in 1966 from the Indarch enstatite chondrite, which fell in Azerbaijan in 1891. It is named after Edwin Roedder, an American expert on fluid inclusions. It was later found in rare volcanic rocks on Earth.
What it is
Roedderite belongs to the osumilite group, silicates built of double rings of silicon–oxygen groups. It is rich in alkali metals and silica and forms at high temperature and low pressure.
Where it is found
It occurs as tiny grains in enstatite chondrites and in some silicate inclusions in iron meteorites. On Earth it has been found in a few high-temperature volcanic rocks.
How it is recognised
It is colourless and microscopic. It is identified by its chemistry, rich in silicon with sodium, potassium and magnesium, and by its crystal structure.
Did you know?
The related mineral merrihueite, with more iron and potassium, was described in the same year from a different meteorite.
Edwin Roedder pioneered the study of tiny drops of fluid trapped in crystals.