Paqueite
A calcium titanium aluminium silicate found in a vanadium-rich inclusion in Allende.
Key facts
- Formula
- Ca3TiSi2(Al,Ti,Si)3O14
- Family
- Silicates
- Crystal system
- Trigonal
- First described
- the Allende CV3 chondrite, 2013
Paqueite was approved as a new mineral in 2013 from a calcium-aluminium-rich inclusion in the Allende meteorite, and fully described in 2022. It is named after Julie Paque, an American cosmochemist who studied these inclusions. It is known only from meteorites.
What it is
Paqueite is a silicate of calcium, titanium and aluminium in which some of the titanium is in the unusual reduced state Ti3+. Reduced titanium forms only where oxygen is very scarce, as it was in the hot gas around the young Sun.
Where it is found
It occurs as tiny crystals in the melilite-rich interior of a type A calcium-aluminium-rich inclusion in Allende, together with burnettite, spinel and perovskite. The inclusion is unusually rich in vanadium.
How it is recognised
It is identified with a scanning electron microscope, electron backscatter diffraction and microprobe analysis.
Did you know?
Paqueite and burnettite were discovered in the same inclusion and described together.
Type A inclusions are named for their high melilite content, not for any order of discovery.