Formation of synthetic spinel in a heated sapphire

Formation of synthetic spinel (probably close to hercynite) in a sapphire heat-treated at high temperature. These spinel formations are relatively common in yellow sapphires, which are also heat-treated at high temperatures. 

🔬: P. Sukkasem

Do you need this micrograph in full resolution for an article, a DUG dissertation, etc.? Do not hesitate to contact us.