The 1.789eV photoluminescence center in diamond grown by using a high-pressure high-temperature technique was considered. It was demonstrated here that this photoluminescence center probably originated, not from a point defect in diamond, but from crystalline Al2O3:Cr3+ (ruby) inclusions in the diamond.

Comment on “Evidence for a Fe-Related Defect Centre in Diamond”. K.Iakoubovskii, G.J.Adriaenssens: Journal of Physics - Condensed Matter, 2002, 14[21], 5459-60