corundum, Sri Lanka.12, inclusions.5, gems

Three-phrase inclusions i n untreated natural color-less, yellow, and blue sapphires from Sri Lanka were found to consist of liquid and gaseous carbon diox-ide cis well as needle-like to tabular crystals of di-aspore. The identification of diaspore was accom-plished through the use of a microscope-mounted drill system and an improved version of the Gandolfi X-ray camera. Technical details for both methods are given. The conditions under which diaspore forms as a daughter mineral in corundum are briefly dis-cussed.