Åkermanite
The magnesium-rich end of the melilite series, found with gehlenite in refractory inclusions.
Key facts
- Formula
- Ca2MgSi2O7
- Family
- Silicates
- Crystal system
- Tetragonal
What it is
Åkermanite is the melilite in which magnesium and silicon replace the extra aluminium of gehlenite. It is named after Anders Åkerman, a Swedish metallurgist. Because it melts at a lower temperature than gehlenite, the zoning between them shows how an inclusion cooled.
Where it is found
It occurs with gehlenite in melilite-rich calcium-aluminium-rich inclusions of CV and other carbonaceous chondrites. The outer zones of melilite crystals are usually richer in åkermanite.
How it is recognised
It has the low birefringence typical of melilite, and is identified by microprobe analysis.
Did you know?
Synthetic åkermanite is studied as a material for bone repair.
The ratio of åkermanite to gehlenite in a crystal changes across a few micrometres, recording its growth.