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Geosciences LibreTexts

16.12: Chrysoberyl

  • Page ID
  • Chrysoberyl
    Chemical composition BeAl2O4
    Crystal system Orthorombic
    Habit Pseudo-hexagonal twins
    Cleavage Weak to moderate
    Fracture Conchoidal to uneven
    Hardness 8.5
    Optic nature Biaxial +
    Refractive index 1.74-1.75
    Birefringence 0.009
    Dispersion Low, 0.014
    Specific gravity 3.72
    Lustre Bright vitreous
    Pleochroism Moderate to strong

    Figure \(\PageIndex{1}\): Chrysoberyl
    Photo courtesy of John Huff,

    Chrysoberyl image gallery

    Chrysoberyl is a beryllium aluminum oxide, not at all related to the mineral beryl, which is a silicate. Chrysoberyl can occur in various shades of green, yellow, brown, red, and occasionally blue. The most valuable varieties of chrysoberyl are alexandrite, and cat's eye. Cat's eye was long admired in the orient for its chatoyant character, but it wasn't popular in the West until the late 1800s. The third and most common variety of chrysoberyl is a transparent greenish yellow stone. It was very popular in Victorian and Edwardian jewelry. Cat's eye is believed to protect one from evil spirits or the evil eye. According to the Hindus, the stone would preserve your health and guard against poverty. In Asia, it was thought that if you pressed a cat's eye between your own eyes it would enhance your foresight.




    Figure \(\PageIndex{2}\): Cat's Eye Chrysoberyl
    Photo courtesy of The Gem Trader

    G&G Articles on Chrysoberyl 1934-1980

    The GIA has published all the G&G's from 1934 until 1980 online. The organization of the list by subject was done by Joseph Gill.