Impregnated Turquoise Gemstone & Information | Gemopedia by JTV | Gemopedia™

Impregnated Turquoise

As it occurs naturally, turquoise is a soft mineral that is easily scratched. Its porous nature can allow the absorption of oils and fluids that can discolor it over time. To improve its durability and appearance, much of the turquoise on the market today is stabilized. One popular method of stabilization is impregnation, which fills the porous areas with a colorless agent, usually plastic.

Colors

Slightly Yellowish Green If Wax Impregnated, Greenish Blue If Impregnated With Plastic

  • Impregnated-turquoise classification

    CommonName
    Impregnated Turquoise
    Species
    Turquoise
    Variety
    Colors
    Slightly Yellowish Green If Wax Impregnated, Greenish Blue If Impregnated With Plastic
    AlternateNames
    Impregnated Turuqois
    GemstoneGroups
    KeySeparations
    RI, magnification, SG, spectrum and acrid smell and sweating effect if hot point test is used
    ClassificationComments
    If stones are heavily treated the RI can be as low as 1.56. If SG is below 2.60 and has fine color it is a fine indication that some impregnation has occurred. Some heavily treated material can have SG's as low as 1.80 to 2.00.
  • Impregnated-turquoise chemistry & crystallography

    ChemicalName
    hydrated copper aluminum phosphate
    ChemicalFormula
    CuAl6(PO4)4(OH)8-5H2O
    Synthesis
    CrystalSystem
    Triclinic
    ChemistryClassification
    Phosphate
    Nature
    Natural
    Crystallinity
    Aggregate
    ChemistryComments
  • Impregnated-turquoise optical properties

    Transparency
    Semitranslucent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.6-1.61
    Birefringence
    0.04
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Inert
    LWUV: Inert to weak greenish yellow
    CCFReaction
    Pleochroism
    None
  • Impregnated-turquoise characteristic physical properties

    Hardness
    5-6
    CharacteristicComments
    Streak
    SpecificGravity
    2.5-2.6
    Toughness
    Varies
    Inclusions
    Impregnated turquoise often has brown, gray or black matrix that is recessed below polished surface. Stones will have a higher luster than natural turquoise. Stones may contain pyrite or calcite inclusions. Stones can have a speckled appearance similar to the "cream-of-wheat" effect if wax impregnated.
    Luster
    Vitreous
    Stability
    Fracture
    Conchoidal, Granular
    Cleavage
    None