Feature Gems & Gemology, Winter 1990, Vol. 26, No. 4

Diagnostic Features and Heat Treatment of Kashmir Sapphires

The locality origin of natural-color blue sapphires from Kashmir can, in many cases, be positively identified. However, the field of origin determination is a very complex one – especially with the now common practice of heat treatment. Today, only by combining different gemological tests with years of practical experience, can a conclusive determination of the origin of a sapphire be made. For all practical purposes, examination of inclusions in conjunction with optical spectrophotometry remain the most important tests.