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Smithsonian National Museum of Natural History


Alexandrites photographed under incandescent lighting.
Photo by Chip Clark. Click to zoom.
SpecimenCatalog NumberLocalityWeight
Chrysoberyl (var. alexandrite)NMNH G2042-00Sri Lanka65.7 ct
Chrysoberyl (var. alexandrite)NMNH G3407-00Sri Lanka16.68 ct
Chrysoberyl (var. alexandrite)NMNH G10065-00Russia4.84 ct


One of the most valuable gemstones is the variety of chrysoberyl known as alexandrite. Alexandrite is renowned for its color change from red under incandescent light, to green in daylight or fluorescent light. Alexandrite was discovered in 1830 in the Ural Mountains of Russia and named after Csar Alexander II. The original locality for alexandrite is Russia, however, fine gems have also been found in Brazil, Sri Lanka, Tanzania, Madagascar, Zimbabwe, India, and Burma. Photographed here is a 65.08 carat square-cushion cut alexandrite from Sri Lanka; a 16.69 carat cushion cut alexandrite from Sri Lanka; and a 4.84 carat emerald cut alexandrite from Russia.



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