Hibonite-(Fe)
An iron-rich hibonite that formed when an ancient inclusion in Allende was altered.
Key facts
- Formula
- (Fe,Mg)Al12O19
- Family
- Oxides
- Crystal system
- Hexagonal
- First described
- the Allende CV3 chondrite, 2009
Hibonite-(Fe) was approved as a new mineral in 2009 from the Allende CV3 chondrite. It is the iron-rich relative of hibonite and is known only from meteorites.
What it is
Hibonite-(Fe) is an aluminium oxide in which iron and magnesium take the place of the calcium of ordinary hibonite. Ordinary hibonite is one of the first minerals to condense from hot solar gas; this iron-bearing form is not, because iron is far more volatile.
Where it is found
It was found in Allende in an altered calcium-aluminium-rich inclusion, where iron was brought in by fluids or gases, probably on the parent asteroid, long after the inclusion formed.
How it is recognised
It is identified by microprobe analysis and electron backscatter diffraction in a scanning electron microscope.
Did you know?
Ordinary hibonite was named after a French prospector who found it in Madagascar.
The suffix (Fe) in a mineral name shows which element dominates one of its sites.