Alexandrite
Hardness 8.5 specific gravity 3.71-75
Refractive index 1.74-76 birefringence 0.008-10
Wear: excellent durability
Alexandrite is a rare variety of chrysoberyl. Because of its chromium content, it has a color changing effect. It is red under tungsten lamp and green under sunlight.
Alexandrite is the birthstone of June.
The history of alexandrite
In 1830, "Alexandrite" was first found in the Ural Mountains of Russia. The "Alexandrite" produced here has an outstanding red and green color changing effect, just two colors of the flag of the "Imperial Russian". This gem was presented to the young Alexander II and was named Alexander rite after the king.
Alexandrite in the Ural Mountains is rarely produced. At present, the most important Alexandrite producing areas in the world are Brazil, Sri Lanka and East Africa.
Alexandrite in Brazil has a high international price. Alexandrite produced in Sri Lanka has a large particle size, often showing a brownish red to yellow green color change effect. Alexandrite produced in India has a small particle size but good quality.
Factors affecting the value of alexandrite
Because the color of Alexandrite is greatly affected by the light, many alexandrites are not as bright as other gemstones.
Alexandrite of the highest quality has a strong red and green discoloration effect. Gemstones of this quality are extremely rare and often very expensive.
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