Hawk's-Eye Quartz Gemstone & Information | Gemopedia by JTV | Gemopedia™

Hawk's-Eye Quartz

Hawks eye quartz is grayish blue in color due to the presence of crocidolite fibers which are intergrown with quartz producing a wavy, chatoyant shimmer. The word chatoyant comes from the French word chatoyer, meaning to shine like a cat's eyes. When the fibers of crocidolite oxidize (a form of alteration due to contact with air), they turn golden brown, producing the related quartz variety, tigers eye.

Colors

Gray To Grayish Blue, Blue Green

  • Hawks-eye-quartz classification

    CommonName
    Hawk's-Eye Quartz
    Species
    Quartz
    Variety
    Hawk's-Eye Quartz
    Colors
    Gray To Grayish Blue, Blue Green
    AlternateNames
    Hawk's-Eye, Falcon's-Eye
    GemstoneGroups
    KeySeparations
    Appearance, RI and SG. Magnification and fluorescence might be helpful.
    ClassificationComments
    Hawk's-eye quartz is a form of tiger's eye where the quartz has replaced by the mineral crocidolite.
  • Hawks-eye-quartz chemistry & crystallography

    ChemicalName
    silicon dioxide (aka silica)
    ChemicalFormula
    SiO2
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Silicate
    Nature
    Natural
    Crystallinity
    Aggregate
    ChemistryComments
  • Hawks-eye-quartz optical properties

    Transparency
    Semitranslucent - Opaque
    Dispersion
    OpticalComments
    RefractiveIndex
    1.544-1.553
    Tolerance:very constant
    Birefringence
    0.009
    OpticCharacter
    Uniaxial
    OpticSign
    Positive
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    None
  • Hawks-eye-quartz characteristic physical properties

    Hardness
    7
    CharacteristicComments
    Streak
    SpecificGravity
    2.64-2.69 Typical:2.66
    Toughness
    Good
    Inclusions
    The cat's-eye of the stone will be the same color as the body of the stone and will be easy to see. Hawk's-eye quartz has a wavy, parallel, fibrous structure and the cat's-eye will have a wavy appearance.
    Luster
    Vitreous
    Stability
    Good
    Fracture
    Splintery
    Cleavage
    None