Kirschsteinite
A calcium–iron olivine-group mineral typical of angrites, the oldest basalts in the Solar System.
Key facts
- Formula
- CaFeSiO4
- Family
- Silicates
- Crystal system
- Orthorhombic
What it is
Kirschsteinite has the olivine structure, but calcium fills half of the metal sites. It forms in melts rich in calcium and poor in silica.
Where it is found
It occurs as exsolution lamellae and zones within calcium-rich olivine in angrites such as Angra dos Reis and D'Orbigny. Angrites crystallised about 4.56 billion years ago, only a few million years after the first solids.
How it is recognised
It is identified with a microprobe, often as thin stripes in olivine grains.
Did you know?
Did you know?
Angrites are named after Angra dos Reis, which fell in Brazil in 1869.
Did you know?
Angrites are so precisely dated that they are used to anchor the early Solar System's timeline.