Turquoise Gemstone & Information | Gemopedia by JTV | Gemopedia™

Turquoise

December's birthstone, turquoise was among the first gemstones ever mined. Stunning sky blues to stimulating sea greens have made turquoise one of the most popular color trends in jewelry history. Copper gives turquoise its range of blue hues while iron is responsible for its green colors. Treasured since the days of ancient Egypt, and the thousands of years since, turquoise is said to bring good fortune and happiness to those who wear it.

Colors

Light To Medium Blue, Greenish Blue To Green, Often Mottled With Brown, Dark Gray, Black Veins.

  • Turquoise classification

    CommonName
    Turquoise
    Species
    Turquoise
    Variety
    Colors
    Light To Medium Blue, Greenish Blue To Green, Often Mottled With Brown, Dark Gray, Black Veins.
    AlternateNames
    Turuqois
    GemstoneGroups
    KeySeparations
    The appearance of turquoise is a primary clue to its identity, especially if a recessed matrix is observed. Other key separations are its refractive index (using a spot reading or distant vision method), spectrum and possibly fluorescence.
    ClassificationComments
    Persian turquoise is an intense, robins egg or sky blue from the Nishapur district of Iran. Stones tend to have a low porosity and take a good polish. Persian turquoise has less dark veining than turquoise form other areas and might have white patches. It is considered to be the best quality of turquoise.Most American or Mexican turquoise is a by product of copper mining. Stones are generally light blue, greenish blue to blueish green and have can have a brown matrix and it is somewhat porous. The Sleeping Beauty Mine turquoise was light blue in color with very little veining. Egyptian turquoise has been depleted but antique stones will have a greenish blue to yellowish green color. Spiderweb turquoise has thin lines of matrix in web like patterns. Turquoise is a alternate birthstone for December.
  • 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
  • Turquoise optical properties

    Transparency
    Semitranslucent - Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    1.61-1.65
    Birefringence
    0.04
    OpticCharacter
    Biaxial
    OpticSign
    Positive
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Inert
    LWUV: Inert to weak greenish yellow
    CCFReaction
    Pleochroism
    None
  • Turquoise characteristic physical properties

    Hardness
    5-6
    CharacteristicComments
    Streak
    White
    SpecificGravity
    2.38-2.86 Typical:2.74
    Toughness
    Varies
    Inclusions
    Turquoise often has brown, gray or black matrix that is sometimes recessed below the polished surface of the stone. Stone may contain pyrite or calcite inclusions.
    Luster
    Vitreous
    Stability
    Fracture
    Granular
    Cleavage
    None