Stanfieldite
A calcium–magnesium phosphate found in pallasites and mesosiderites.
Key facts
- Formula
- Ca4(Mg,Fe)5(PO4)6
- Family
- Phosphates
- Crystal system
- Monoclinic
- First described
- stony-iron meteorites, 1967
Stanfieldite was described in 1967 from stony-iron meteorites, including pallasites and mesosiderites. It has been found mainly in meteorites.
What it is
Stanfieldite is a phosphate of calcium, magnesium and iron. It forms where phosphorus from metal reacts with silicates.
Where it is found
It occurs in pallasites, mesosiderites and some lunar rocks, usually at the contact between metal and silicate, sometimes with farringtonite and merrillite.
How it is recognised
It is colourless to amber and identified with a microprobe.
Did you know?
Stanfieldite is one of several phosphates that exist only where phosphorus was released from meteoritic metal.
Mesosiderites are mixtures of metal and crustal rock from an asteroid broken up and reassembled.