Color Change Sapphire Gemstone & Information | Gemopedia by JTV | Gemopedia™

Color Change Sapphire

While color change sapphires come from a variety of locations, the gem gravels of Tanzania are the main source. Color change sapphires present gem lovers with an opportunity to own the rare and stunning color change effect in a gem other than alexandrite, garnet, spinel, tourmaline or diaspore. While the colors tend to vary depending on locale, in general they change from blue to purple. You can observe color change in this gem by viewing it interchangeably in natural and incandescent light.

Colors

Pink-Brown Through Brownish Pink, Purple Changing To Yellowish Brown, Grayish Violet, Grayish Blue, Green

  • Color-change-sapphire classification

    CommonName
    Color Change Sapphire
    Species
    Corundum
    Variety
    Color Change Sapphire
    Colors
    Pink-Brown Through Brownish Pink, Purple Changing To Yellowish Brown, Grayish Violet, Grayish Blue, Green
    AlternateNames
    GemstoneGroups
    KeySeparations
    RI, birefringence, magnification and color change
    ClassificationComments
    Will have a spectra similar to ruby and pink sapphire.
  • Color-change-sapphire chemistry & crystallography

    ChemicalName
    aluminum oxide
    ChemicalFormula
    Al2O3
    Synthesis
    CrystalSystem
    Trigonal
    ChemistryClassification
    Oxide
    Nature
    Natural
    Crystallinity
    Crystalline
    ChemistryComments
  • Color-change-sapphire optical properties

    Transparency
    Transparent - Semitranslucent
    Dispersion
    Strength: weak fire Value: 0.018
    OpticalComments
    RefractiveIndex
    1.762-1.77
    Tolerance:(+0.009/-0.005)
    Birefringence
    0.008-0.01
    OpticCharacter
    Uniaxial
    OpticSign
    Negative
    PolariscopeReaction
    Doubly Refractive (DR)
    Fluorescence
    SWUV: Inert
    LWUV: Inert
    CCFReaction
    Pleochroism
    Dichroic, varies with bodycolor
  • Color-change-sapphire characteristic physical properties

    Hardness
    9
    CharacteristicComments
    Streak
    White
    SpecificGravity
    4.1-3.95 Typical:4
    Toughness
    Excellent
    Inclusions
    This stone has a type II clarity. Color change sapphire sometimes have silk composed of rutile needles, dark brown crystals, boehmite or zircon crystals. Stones might have fingerprint or 2-phase inclusions. Hexagonal growth and strong color zoning are possible in some stones. Untreated stones will usually have inclusions intact. Heat treated stones will have fracture halos or snowballs around crystal inclusions(untreated stones from magmatic areas might also show these characteristics). Silk will be broken and might show sintered areas especially around the girdle.
    Luster
    SubAdamantine
    Stability
    Very Good
    Fracture
    Conchoidal
    Cleavage
    None