Sapphire (Synthetic Floating Zone) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Sapphire (Synthetic Floating Zone)

One method of creating synthetic sapphire is called floating zone. In this method of gem synthesis, originally developed by engineers to create super pure silicon, a sintered rod of powdered material, comprised of elements necessary for the gem to grow, is heated with infrared radiation in a vacuum while the ends of the rod are rotated in opposite directions. Since all impurities including air are removed during crystallization, very clean crystals can form.

Colors

Light Pink, Pink, Reddish Purple, Purple

  • Sapphire-synthetic-floating-zone classification

    CommonName
    Sapphire (Synthetic Floating Zone)
    Species
    Corundum
    Variety
    Floating-Zone Synthetic Fancy Sapphire
    Colors
    Light Pink, Pink, Reddish Purple, Purple
    AlternateNames
    Lab Created Synthetic Fancy Sapphire
    GemstoneGroups
    KeySeparations
    Magnification and RI, birefringence, pleochroism
    ClassificationComments
  • Sapphire-synthetic-floating-zone chemistry & crystallography

    ChemicalName
    aluminum oxide
    ChemicalFormula
    Al2O3
    Synthesis
    floating-zone
    CrystalSystem
    Trigonal
    ChemistryClassification
    Oxide
    Nature
    Synthetic
    Crystallinity
    Crystalline
    ChemistryComments
  • Sapphire-synthetic-floating-zone optical properties

    Transparency
    Transparent - Opaque
    Dispersion
    Strength: moderate 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: moderate to strong red
    LWUV: strong red
    CCFReaction
    Pink: weak red
    Pleochroism
    Dichroic, moderate, varying shades of body color
  • Sapphire-synthetic-floating-zone characteristic physical properties

    Hardness
    9
    CharacteristicComments
    Streak
    White
    SpecificGravity
    3.95-4.1 Typical:4
    Toughness
    Excellent
    Inclusions
    Stones are almost always inclusion free. If internal characteristics are present they are gas bubbles that are not perfectly round and swirls of color.
    Luster
    SubAdamantine
    Stability
    Very Good
    Fracture
    Conchoidal
    Cleavage
    None