Deltalumite

This article is a stub. It needs to be expanded.

A polymorph of leukosapphire.
This compound/material/gemstone is interesting because normally Al₂O₃ forms leukosapphire (corundum structure).

Al₂O₃ Deltalumite (δ form of corundum, polymorph of sapphire) – tetragonal – Mohs ?? (likely quite hard) – [1]

Its structural formula can be written as (Al_0.67◻_0.33)Al₂O₄, where ◻ is a vacancy.

Oxospinel type structure.

External links