Cronusite
A hydrated calcium chromium sulphide that forms when a meteorite mineral weathers on Earth.
Key facts
- Formula
- Ca0.2(H2O)2CrS2
- Family
- Sulphides
- Crystal system
- Trigonal
- First described
- the Norton County aubrite, 2002
Cronusite was approved as a new mineral in 2002 from the Norton County aubrite. It is named after Cronus, the Titan of Greek myth whose parents were the sky and the earth, because the mineral forms when a meteorite mineral reacts with Earth's moisture.
What it is
Cronusite is a layered chromium sulphide with calcium ions and water molecules between the layers. It is closely related to schöllhornite, which has sodium in place of calcium. Both form by the alteration of caswellsilverite, a sodium chromium sulphide.
Where it is found
It occurs in the Norton County aubrite, where caswellsilverite has reacted with water since the fall in 1948.
How it is recognised
It is identified by its composition and structure using microprobe analysis and X-ray diffraction.
Did you know?
Cronusite is a mineral half from space and half from Earth: its sulphide came from the asteroid, its water from our planet.
Layered sulphides like it can swap the ions between their layers, like a battery material.