Fluor-richterite
A sodium-rich amphibole with fluorine, found in enstatite chondrites and aubrites.
Key facts
- Formula
- Na(NaCa)Mg5Si8O22F2
- Family
- Silicates
- Crystal system
- Monoclinic
What it is
Fluor-richterite is an amphibole, a double-chain silicate, in which fluorine fills the sites usually held by hydroxyl. Amphiboles usually need water to form, so a fluorine-bearing one in a dry, oxygen-poor meteorite is a curiosity.
Where it is found
It occurs as rare grains in EL and EH enstatite chondrites and in some aubrites, together with enstatite, albite and sulphides.
How it is recognised
It is identified by microprobe analysis showing fluorine and sodium, and by its two cleavages at about 56 and 124 degrees.
Did you know?
Did you know?
Kaersutite, another amphibole, is found in Martian meteorites and holds clues to water on Mars.
Did you know?
Fluorine-bearing minerals are rare in meteorites.