Alexandrite (Synthetic Cat's Eye) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Alexandrite (Synthetic Cat's Eye)

The term cat's eye, or chatoyancy, is used to describe a phenomenal optical property in gemstones, in this case synthetic chrysoberyl. The effect, when present, appears as a bright, narrow slit similar to the pupils in the eyes of your favorite feline. This phenomenon is caused by parallel fibrous or needle-like inclusions that interfere with the passage of light throughout the crystal, scattering and reflecting light back to the viewer as a thin line. Chatoyant synthetic chrysoberyl is particularly incredible because it exhibits two rare phenomena in gemstones: both the cat's eye affect and color change. The term synthetic refers to a man-made material with a natural counterpart that shares the same (or nearly identical) chemical, optical, and physical properties. Synthetic color change chrysoberyl presents gem lovers with an opportunity to own the stunning color change effect so prized in gems.

Colors

Bluish Green In Daylight, Fluorescent Light, Brownish Red To Purple-Red In Incandescent

  • Alexandrite-synthetic-cats-eye classification

    CommonName
    Alexandrite (Synthetic Cat's Eye)
    Species
    Chrysoberyl
    Variety
    Synthetic Cat's-Eye Alexandrite
    Colors
    Bluish Green In Daylight, Fluorescent Light, Brownish Red To Purple-Red In Incandescent
    AlternateNames
    GemstoneGroups
    KeySeparations
    Magnification, fluorescence, cat's-eye appearance and color change, RI, SG and spectrum. Strong red fluorescence might be an indicator of synthetic.
    ClassificationComments
  • Alexandrite-synthetic-cats-eye chemistry & crystallography

    ChemicalName
    beryllium aluminum oxide
    ChemicalFormula
    BeAl2O4
    Synthesis
    pulled and floating zone
    CrystalSystem
    Orthorhombic
    ChemistryClassification
    Oxide
    Nature
    Synthetic
    Crystallinity
    Crystalline to Aggregate
    ChemistryComments
  • Alexandrite-synthetic-cats-eye optical properties

    Transparency
    Semitransparent
    Dispersion
    Strength: weak fire Value: 0.015
    OpticalComments
    RefractiveIndex
    1.746-1.755
    Tolerance:(+0.004/-0.006)
    Birefringence
    0.008-0.01
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: moderate to strong red
    LWUV: moderate to strong red
    CCFReaction
    red
    Pleochroism
    Unobservable
  • Alexandrite-synthetic-cats-eye characteristic physical properties

    Hardness
    8.5
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3.71-3.75 Typical:3.73
    Toughness
    Excellent
    Inclusions
    Pulled synthetic cat's-eye alexandrite might show needles and curved striae. Floating zone synthetic stones can have gas bubbles and show a swirled appearance. Undulating growth lines can be seen in some stones.
    Luster
    SubAdamantine
    Stability
    Very Good
    Fracture
    Conchoidal
    Cleavage
    Good, in one direction