Alexandrite
from the Antique Jewelry University
Alexandrite, a chrysoberyl variety, possesses a distinct change of color when viewed under different (incandescent and fluorescent) light sources. The change in color is caused by trace amounts of chromium and vanadium. The amounts of these minor trace elements in the chrysoberyl lattice may vary depending on geographical location. This extra-ordinary gemstone was discovered in 1834 in the Russian Ural mountain range and named in honor of the, future, Russian Tsar Alexander II as it was discovered on his birthday. The finest examples of alexandrite exhibit a color change from an amethyst like purplish-red in incandescent to teal emerald green in daylight (or fluorescent light). The famous mineralogist George F. Kunz (1856-1932), chief gemologist and vice-president to Tiffany & Co., popularized this rare gemstone in the western hemisphere. Although there have not been many alexandrites found in Russia during the last century, the high quality of stones from that deposit set the standard of fineness by which all others are judged.
Today most gem quality material comes from Brazil and the finest stones have a color change from a lively bright purplish-red to bluish-green. Other deposits are located in India, Madagascar and Sri Lanka. Alexandrite in sizes over 3 carats are very rare, although a 60 carat crystal has been found in Sri Lanka. Prices of fine quality alexandrite are in par with this rarity.
Alexandrite is the anniversary gemstone for the 55th year. Because of the rarity of alexandrite, genuine stones are often substituted with a variety of synthetic sapphire that exhibits a slight color change from blue to purple.
As alexandrite is a fairly recent find it does not have a wide spread talismanic use. In Russia, alexandrite is often associated with luck and prosperity. Other attributes are the ability to aid in problems with the nervous system, spleen, pancreas & testicles. Alexandrite is also associated with several mystical properties, including reinforcing one's self esteem and balancing positive and negative energy.
| Gemological information for alexandrite | |
|---|---|
| Color | Red and green (color change) |
| Crystal structure | Orthorhombic |
| Family | Chrysoberyl |
| Refractive index | 1.746-1.755 |
| Durability | Excellent |
| Hardness | 8.5 |
| Similar stones | There are some other stones which exhibit an alexandrite effect: natural and synthetic sapphire, garnet, synthetic spinel, zultanite (diaspore), synthetic cubic zirconia |
| Treatments | None known |
| Country of origin | Russia, Brazil, Burma, Sri Lanka, Madagascar, Tanzania And Rhodesia |
| Alexandrite care | |
| Ultrasonic cleaning | Safe |
| Steam cleaning | Safe |
| Warm soapy water | Safe |
| Chemical attact | No reaction |
| Light sensitivity | Stable |
| Heat sensitivity | Stable |