Lot 3210. Exceptional Chrysoberyl var. Alexandrite, Sri Lanka. Weighing approximately 18.03 carats and measuring 15.87 x 13.54 x 10.19mm. Estimate US$ 200,000 - 250,000 (€ 170,000 - 210,000). © Bonhams 2001-2018

Named for Tsar Alexander II, this rare and beautiful gem, of top quality, is hardly ever used in modern jewelry. In antique Russian jewelry you may come across it with a little luck, since Russian master jewelers loved this stone. Tiffany's master gemologist George Frederick Kunz (1856-1932) was also fascinated by alexandrite, and the jeweler's firm produced some beautiful rings and platinum ensembles at the turn of the last century. Smaller alexandrites were occasionally also used in Victorian jewelry from England.  

The present stone is large for the species. It is a classic for the locality and for this species: a lovely old world cushion-cut, Chrysoberyl variety Alexandrite which is notable for its exceptional degree of color change from purplish red incandescent light to bluish green in fluorescent light. This stone is an excellent choice for the serious collector. 

Accompanied by an American Gemological Laboratories Prestige Gemstone Report numbered 1082294 dated March 8, 2017 stating that the 18.03 carats stone is a Natural Chrysoberyl variely Alexandrite and that it changes from brownish green to pinkish brown with a degree of color change which is prominent to strong (80-90%) and that it is a classic Sri Lankan stone without enhancements.

Bonhams. THE WORLD OF GOLD, OPALS AND OTHER "PHENOMENAL" GEMS, 15 May 2018, 10:00 PDT, LOS ANGELES