Akoya Pearl Gemstone & Information | Gemopedia by JTV | Gemopedia™
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.
White, Cream Pink, Yellow, Blue With Rose, Green Overtone
Akoya-pearl classificationCommonNameAkoya PearlSpeciesNAVarietyAkoya PearlColorsWhite, Cream Pink, Yellow, Blue With Rose, Green OvertoneAlternateNamesAkoya-GaiGemstoneGroupsKeySeparationsAppearance, 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.ClassificationCommentsTypical 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 & crystallographyChemicalNamecalcium carbonate + conchiolin and waterChemicalFormulaCaCO3SynthesisCrystalSystemNAChemistryClassificationOrganicNatureCulturedCrystallinityChemistryComments
Akoya-pearl optical propertiesTransparencyTranslucent - OpaqueDispersionOpticalCommentsRefractiveIndex1.53-1.685Birefringence0.155OpticCharacterNAOpticSignNAPolariscopeReactionAggregate (AGG)FluorescenceSWUV: Variable
Akoya-pearl characteristic physical propertiesHardness2.5-4CharacteristicCommentsStreakSpecificGravity2.72-2.78ToughnessGoodInclusionsAkoya pearls have an intense luster and iridescent surface. If the pearl is drilled you can inspect the hole to look for bead nucleus.LusterDullStabilityPoorFractureUnevenCleavageNone