Alexandrite

This rare gemstone, its variety displays a colour change which is also called alexandrite effect, depends upon light along with strong pleochroism. Alexandrite results from small scale replacement of aluminum by chromium oxide, which is responsible for alexandrite’s characteristic green to red colour. The ideal colour change would be fine emeral green to fine purplish red, but this is rare.

Beautiful alexandrite in top quality, however, is very rare indeed and hardly ever used in modern jewellery. In antique Russian jewellery you may come across it with a little luck, since Russian master jewellers loved this stone. Tiffany’s master gemmologist George Frederick Kunz (1856-1932) was also fascinated by alexandrite, and the jeweller’s firm produced some beautiful series of rings and platinum ensembles at the end of the 19th and beginning of the 20th century. Smaller alexandrites were occasionally also used in Victorian jewellery from England.