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Differences Between Russian and Brazilian Alexandrite

Alexandrite is a very rare gemstone of the chrysoberyl family. Named for the Russian czar Alexander after its discovery near emerald mines in the Ural mountains in 1934, it became very popular with jewelers and nobility in czarist Russia. Exhibiting green and red hues, the national colors of the nation, it eventually became the national gemstone of this monarchy. Known for its scarcity, top quality alexandrite is so rare that it is hardly ever used in modern jewelry. Today, alexandrite is also found in Sri Lanka and Brazil. Brazilian and Russian alexandrite gems share certain characteristics, but there are differences.

Color
- Alexandrite is a very unusual gemstone. It changes color according to light conditions. In bright natural light, it is green or bluish green; under artificial light, it changes to a soft red, raspberry red or purplish-red. Russian alexandrite tends to have a richer green color than stones from Brazil. The color change exhibited by Brazilian alexandrite is also not as pronounced as Russian stones.
Chatoyancy
- Brazilian alexandrites sometimes exhibit a characteristic known as chatoyancy. Chatoyancy is an optical effect created by impurities in the gemstone. This effect manifests as a glowing line of reflected light running along one axis of the stone; this is sometimes called a "cat's eye." Sometimes, more than one such line is present. These are called "stars." Russian stones do not exhibit this characteristic.
Rarity and Value
- Russian stones are considerably rarer than stones from other regions. Russian alexandrite deposits were worked out many decades ago. These stones are generally of superior quality to gems found in other areas of the world. This combination of rarity and quality makes Russian alexandrite one of the most valuable gems in the world; faceted specimens greater than one carat in weight are more valuable than comparable sapphires, rubies, diamonds or emeralds.

Gemology