alexandrite

Note: As recounted in the first detailed published description of the mineral by the Finnish mineralogist Nils Gustaf Nordenskiöld (1792-1866), the gemstone was named in honor of Aleksandr Nikolaevič, it having been discovered in the Urals on his sixteenth birthday (April 17, 1834, old style) (see Schriften der in St. Petersburg gestifteten Russisch-Kaiserlichen Gesellschaft für die gesammte Mineralogie, 1. Band, 1. Abtheilung, St. Petersburg, 1842, pp. cxvi-cxxvi). According to a story promulgated on the website alexandrite.net (and copied in Wikipedia, as of 4/30/2019), the stone was considered an emerald until its color-changing property was first discovered by Nordenskiöld, who initially wished to name it "diaphanite"; he was allegedly overruled by the imperial official Count Lev Alekseevič Perovskij, who insisted on alexandrite. The details of this story are either demonstrably false or undocumented, and it should probably be considered apocryphal (see Karl Schmetzer and George Bosshart, Russian Alexandrites/Russkie aleksandrity, Stuttgart, Schweizerbart, 2010; M.S. Lejkum et al., Zagadočnyj kamenʼ carja Aleksandra (ob aleksandrite, Aleksandre II i ne tolʼko o nix), izdanie 2-oe, Ridero, 2016). Nordenskiöld did in fact name a mineral Diphanit, but it is a form of margarite with no connection to alexandrite (see "Beschreibung des Diphanit, eines neuen Minerals aus den Smaragdgruben des Urals unweit Katharinenburg," Bulletin de la Class Physico-Mathémathique de l'Académie Impériale des Sciences de St.-Pétersbourg, tome 5. [1847], pp. 265-66).