Olsenite
A potassium iron phosphate from the El Ali iron meteorite.
Key facts
- Formula
- KFe4(PO4)3
- Family
- Phosphates
- Crystal system
- Orthorhombic
- First described
- the El Ali iron meteorite, 2022
Olsenite was approved as a new mineral in 2022 from the El Ali iron meteorite. It is named after Edward Olsen, an American meteorite mineralogist who studied the phosphates and other minerals of iron meteorites. It has since been found in another Somali iron meteorite.
What it is
Olsenite is a phosphate of potassium and iron. The same compound has long been made in laboratories. Potassium is rare in iron meteorites, so its presence says something about the small pockets of trapped material in which these phosphates grew.
Where it is found
It forms grains a few micrometres across in phosphate and sulphide inclusions in the metal of the El Ali IAB iron, touching troilite, elaliite and the iron phosphate graftonite.
How it is recognised
It is identified by electron microprobe analysis and electron diffraction.
Did you know?
Edward Olsen was the first to find phosphate minerals in iron meteorites.
Its sodium relative, galileiite, is also known from iron meteorites but has a different structure.