Akoya Pearl Gemstone & Information | Gemopedia by JTV | Gemopedia™

Akoya Pearl

Akoya pearls tend to be the most consistently round and near-round pearls, which makes them perfect for matching for multi-pearl jewelry. Akoyas are saltwater pearls prized for their roundness, luster and color. They tend to be small, ranging from two to 11 millimeters, as the akoya oyster is the smallest producing oyster, and are considered the "classic" pearl, with their generally white to cream color, with rose or silver overtones.

Colors

White, Cream Pink, Yellow, Blue With Rose, Green Overtone

  • Akoya-pearl classification

    CommonName
    Akoya Pearl
    Species
    NA
    Variety
    Akoya Pearl
    Colors
    White, Cream Pink, Yellow, Blue With Rose, Green Overtone
    AlternateNames
    Akoya-Gai
    GemstoneGroups
    KeySeparations
    Appearance, RI, birefringence blink and magnification. A "tooth test" is commonly used in which a pearl is rubbed against a tooth; if gritty, this is an indication that the surface is nacre, versus plastic and glass imitations that feel smooth.
    ClassificationComments
    Typical size of akoya pearls are 2 to 11mm. They have the highest luster among pearls. They are produced by the Pinctada martensii (Pinctada fucata) mollusk.
  • Akoya-pearl chemistry & crystallography

    ChemicalName
    calcium carbonate + conchiolin and water
    ChemicalFormula
    CaCO3
    Synthesis
    CrystalSystem
    NA
    ChemistryClassification
    Organic
    Nature
    Cultured
    Crystallinity
    ChemistryComments
  • Akoya-pearl optical properties

    Transparency
    Translucent - Opaque
    Dispersion
    OpticalComments
    RefractiveIndex
    1.53-1.685
    Birefringence
    0.155
    OpticCharacter
    NA
    OpticSign
    NA
    PolariscopeReaction
    Aggregate (AGG)
    Fluorescence
    SWUV: Variable
    LWUV: Variable
    CCFReaction
    Pleochroism
    None
  • Akoya-pearl characteristic physical properties

    Hardness
    2.5-4
    CharacteristicComments
    Streak
    SpecificGravity
    2.72-2.78
    Toughness
    Good
    Inclusions
    Akoya pearls have an intense luster and iridescent surface. If the pearl is drilled you can inspect the hole to look for bead nucleus.
    Luster
    Dull
    Stability
    Poor
    Fracture
    Uneven
    Cleavage
    None