Scallop Pearls Gemstone & Information | Gemopedia by JTV | Gemopedia™
A non-nacreous calcareous concretion, scallop pearls may form in any member of the scallop family. A very rare occurrence, such pearls are typically collected by fishermen as a result of harvesting the meat of the shellfish. They are found in the coastal waters of Central and North America, especially Baja California. Unlike other calcareous concretions, scallop pearls are a maroon to plum color and often form in oval, drop-like shapes.
Brown, Tan, Purple, Yellow, Orange Interior Color White, Root Beer Color
Scallop-pearls classificationCommonNameScallop PearlsSpeciesPearlVarietyColorsBrown, Tan, Purple, Yellow, Orange Interior Color White, Root Beer ColorAlternateNamesLion's Paw Pearl, Digby Scallop PearlsGemstoneGroupsKeySeparationsAppearance, 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.ClassificationCommentsLion's paw pearls are produced by the lion's paw scallop Nodipecten subnodosus and can originate from the coast of Central America, Baja California and the inland Sea of Cortx in Mexico. Atlantic Sea Scallop (Placpecten magellanicus) produces the scallop pearls that come from Digby, Nova Scotia.Atlantic sea scallops are produced by the North Atlantic deep-sea scallop, Placopecten magellanicus; the Atlantic bay scallop, Argopecten irradians, and the Atlantic Lion's Paw, Nodipecten nodosus.
Scallop-pearls chemistry & crystallographyChemicalNamecalcium carbonate + conchiolin and waterChemicalFormulaCaCO3SynthesisCrystalSystemNAChemistryClassificationOrganicNatureNaturalCrystallinityAggregateChemistryComments
Scallop-pearls optical propertiesTransparencyTranslucent - OpaqueDispersionOpticalCommentsRefractiveIndex1.53-1.685Birefringence0.155OpticCharacterNAOpticSignNAPolariscopeReactionAggregate (AGG)FluorescenceSWUV:
Scallop-pearls characteristic physical propertiesHardness2.5-4.5CharacteristicCommentsStreakSpecificGravity2.61-2.85ToughnessGoodInclusionsLion's paw pearls sometimes have platelets that display adventuresence. They have a fibrous structure that has a patchwork like appearance. Lion's paw pearls are brown, purple, yellow and orange with an interior color of white, purple or root beer colorDigby scallop pearls are white or pale tan in color and have a silvery sheen. The appearance has roughly circular patches with a radiating pattern caused by parallel calcite fibers.LusterDullStabilityPoorFractureUnevenCleavageNone