Chrysoberyl Cat's Eye

Crystal Structure: Orthorhombic
Composition: Al2(BeO4)Beryllium Aluminum oxide
Hardness:8.5
SG:3.71
RI:1.74-1.75
DR:0.011
Luster:Vitreous

Chrysoberyl occurs is a range of colors, from green, greenish yellow, and yellow to brown. It is a hard, durable stone, particularly suitable for use in jewelry. Two varieties, alexandrite and cat's eye have unique qualities of there own. The vary rare and valuable alexandrite changes from green in daylight to red, mauve or brown under incandescent light.  Cat's eye when cut in cabochon has a near white line across a yellowish gray stone due to canal or feather like fluid inclusions or needle like inclusions of rutile. The most highly prized cat's eye color is light golden brown often with a shadow that gives a light dark, "milk and Honey" effect. Yellow Chrysoberyl popular in Portuguese jewelry of the 18th and 19th centuries ws also known as chrysolite.
OCCURRENCE: Although most has been mined out, the best chrysoberyl, including Alexandrite, has been found in mica schists in the urals (Russia). The largest faceted chrysoberyl from russia weights 66 carats. Lardge water worn pebbles of various colors are found in the gem gravels of Sri Lanks. Chrysoberyl also occurs in Myanmar, Brazil, Zimbabwe, Tanzania, and Madagascar. Cat's eys is found in Sri Lanka, Brazil and China.
REMARKS: The name chrysoberly is from the Greek Chrysos , meaning golden, and beryllos, which refers to beryllium content. Known for thousands of years in Asia, it was highly valued for protection it afforded from the "evil Eye".

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