Davisite
A scandium-rich pyroxene from an ultra-refractory inclusion in Allende.
Key facts
- Formula
- CaScAlSiO6
- Family
- Silicates
- Crystal system
- Monoclinic
- First described
- the Allende CV3 chondrite, 2009
Davisite was described in 2009 from a refractory inclusion in the Allende meteorite, which fell in Mexico in 1969. It is named after Andrew Davis, an American cosmochemist. It is known only from meteorites.
What it is
Davisite is a pyroxene related to diopside in which scandium and aluminium replace magnesium and some silicon. Scandium is one of the elements that condense at the highest temperatures from a hot gas.
Where it is found
It occurs in rare ultra-refractory inclusions in CV chondrites, which formed at even higher temperatures than ordinary CAIs, among the first solids in the Solar System.
How it is recognised
It forms grains only a few micrometres across and is identified with an electron microscope and electron backscatter diffraction, which reads the crystal structure from the pattern of scattered electrons.
Did you know?
Allende has yielded more than 15 minerals new to science.
Ultra-refractory inclusions are enriched in scandium, zirconium and the rare earth elements.