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

Tahitian pearls, grown around Tahiti and French Polynesia, display a shimmering orient or overtone that is green, blue, pink or violet in color. These orient colors are in striking contrast to their silver to black body color and are sometimes given specific names (e.g., deep green is called fly wing; peacock is used for the combination of green and pink; eggplant is a dark toned body color combined with pink).
Colors
Silver, Cream, Brown To Black, Gray, Blue, Green, Yellowish Green, Purple With Green, Rose Overtone.
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Tahitian-pearl classification
CommonNameTahitian PearlSpeciesNAVarietyTahitian PearlColorsSilver, Cream, Brown To Black, Gray, Blue, Green, Yellowish Green, Purple With Green, Rose Overtone.AlternateNamesBlack PearlGemstoneGroupsKeySeparationsAppearance, 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 Tahitian pearls run 8 to 14mm. They are produced by black-lip mollusk Pinctada margaritifera in French Polynesia. -
Tahitian-pearl chemistry & crystallography
ChemicalNamecalcium carbonate + conchiolin and waterChemicalFormulaCaCO3SynthesisCrystalSystemNAChemistryClassificationOrganicNatureCulturedCrystallinityChemistryComments -
Tahitian-pearl optical properties
TransparencyTranslucent - OpaqueDispersionOpticalCommentsRefractiveIndex1.53-1.685Birefringence0.155OpticCharacterNAOpticSignNAPolariscopeReactionAggregate (AGG)FluorescenceSWUV: Variable
LWUV: VariableCCFReactionPleochroismNone -
Tahitian-pearl characteristic physical properties
Hardness2.5-4CharacteristicCommentsStreakSpecificGravity2.72-2.78ToughnessGoodInclusionsTahitian pearls have Intense luster and iridescent surface. If the pearl is drilled you can inspect the hole to look for bead nucleus.LusterDullStabilityPoorFractureUnevenCleavageNone