The Nature of the Be-Nb-Ta Containing Cloud in Natural Madagascar Blue Sapphire – An FIB/HRTEM Study
June 14, 2024
Detecting beryllium in sapphires and rubies has been a critical test in modern gemological laboratories ever since beryllium-diffusion was discovered as a color-enhancing treatment in the early 2000s. However, beryllium is also occasionally detected in natural untreated corundums, which added complications to beryllium testing during the early days of its implementation. Natural beryllium in sapphire is almost always associated with heavy high field strength elements (HHFSEs) such as niobium, tantalum, and tungsten, and is often unevenly distributed in milky or cloudy regions of a stone. This report is the first investigation on the nature of the nano-inclusions in the milky regions of natural beryllium-bearing sapphires.
Dr. Andy Shen, formerly a GIA researcher, is a professor at the Gemmological Institute, China University of Geosciences in Wuhan. He is also editor-in-chief of The Journal of Gems and Gemmology.
