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Geosciences LibreTexts

16.14.04: Indicolite

  • Page ID
    4345
  • Indicolite Tourmaline
    Chemical composition Complex borosilicate
    Crystal system Trigonal
    Habit Prismatic
    Cleavage None
    Fracture Conchoidal
    Hardness 7.5
    Optic nature Uniaxial -
    Refractive index 1.62 - 1.64
    Birefringence 0.014 - 0.022
    Dispersion Low, 0.018
    Specific gravity 3.06
    Lustre Vitreous
    Pleochroism Weak to strong

    File:Indicolite2.jpg

    Figure \(\PageIndex{1}\): Indicolite Tourmaline
    Photo courtesy of Lembeck Gems