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Geosciences LibreTexts

16.46: Lapis Lazuli

  • Page ID
    4733
  •  

    Lapis Lazuli
    Chemical composition rock consisting of lazurite, hauyne, calcite and pyrite
    Habit aggregate
    Fracture uneven
    Hardness 5.5
    Refractive index 1.500 - 1.670
    Specific gravity 2.50 - 3.00
    Lustre resinous to vitreous

    Figure \(\PageIndex{1}\): Lapis Lazuli with Pyrite inclusions

     

    Enhancements

    Common enhancements to lapis lazuli:

    • Fracture filling - wax (with dye or without) - conceal cracks and fractures and to improve luster
    • Dye - color staining - to produce evenly colored material

    Images

    File:Lapis Afghanistan.jpg

    Figure \(\PageIndex{2}\): Untreated lapis lazuli cabochon from Afghanistan.
    Image courtesy of Scott Davies.