Chrysoberyl · June birthstone
Alexandrite
Emerald by day, ruby by night: the colour-change chrysoberyl.
- Hardness
- Mohs 8.5
- Toughness
- Excellent
- Daily wear
- Excellent for daily rings
- Price tier
- USD 3,000 to 30,000+ per carat, fine quality
- Colours
- Green to red (colour change), Teal to purple
- Origins
- Brazil, Sri Lanka, Russia (historic), Tanzania
Alexandrite is chrysoberyl that changes colour with the light source: green to blue-green in daylight, red to purplish red under incandescent light. Fine stones with a strong, clean change are among the rarest gems; the historic Russian source is exhausted and Brazil and Sri Lanka supply small quantities. Very hard and tough, it suits daily wear perfectly, if you can find and afford one.
How to buy alexandrite
The strength and cleanness of the colour change decide the price; a weak change or muddy colours are worth far less. Buy only with a laboratory report, as synthetics are common and convincing.
Treatments
None; synthetic alexandrite is common and must be disclosed.
Care
Warm soapy water; ultrasonic is safe.
Lore
Discovered in the Urals in 1830 and named for the future Tsar Alexander II; its red and green were Imperial Russia’s military colours.
