This padparadscha sapphire from Sri Lanka displayed unusual ghost crystals, several of which were cut through on the surface. In reflected light at the surface, they were detectable only by the inclusions in the crystals themselves, showing no difference in luster from the surrounding sapphire, but stood out brilliantly between crossed polars. This identified them as corundum in corundum. Edward Gübelin first identified corundum in corundum in 1940.
Natural Padparadscha Sapphire • Sri Lanka (Ceylon) • Enhancements: None Detected (None) • Lighting Conditions: Diffuse Light Field + Crossed Polars
Photographer: Richard W. Hughes •
Image Number: A-003-4093-1 • Date Posted: 15 July 2019
Gübelin, E.J. (1948) Gemstone inclusions. Journal of Gemmology, Vol. 1, No. 7, July, pp. 7–39; RWHL*.