Schöllhornite
A hydrated sodium chromium sulphide formed by weathering of caswellsilverite.
Key facts
- Formula
- Na0.3CrS2·H2O
- Family
- Sulphides
- Crystal system
- Trigonal
- First described
- the Norton County aubrite, 1985
Schöllhornite was approved as a new mineral in 1985 from the Norton County aubrite. It is named after Robert Schöllhorn, a German chemist who studied layered sulphides.
What it is
Schöllhornite is a layered chromium sulphide with sodium and water between the layers. It forms when caswellsilverite, a water-free sodium chromium sulphide, takes up water and loses some sodium.
Where it is found
It occurs in the Norton County aubrite as an alteration product of caswellsilverite, formed on Earth after the fall.
How it is recognised
It is identified by microprobe analysis and X-ray diffraction.
Did you know?
Schöllhornite is one of a family of chromium sulphides found mainly in enstatite meteorites.
Its formation shows that even a carefully curated meteorite reacts slowly with the air.