Ivory Gemstone & Information | Gemopedia by JTV | Gemopedia™
Ivory has long been treasured for its beautiful white color and ability to be finely carved. As opposed to bone or horn, ivory is derived from the teeth and tusks of animals. Because of the devastating impact of poaching due to the ivory trade, the importation and sale of such materials is severely restricted or banned in many countries.
White To Light Yellow
Ivory classificationCommonNameIvorySpeciesIvoryVarietyColorsWhite To Light YellowAlternateNamesGemstoneGroupsKeySeparationsRI, magnification, SG and possible fluorescenceClassificationCommentsThe trade on new elephant ivory has been banned sine 1991.Mammoth or mastodon ivory can have a hardness up to 5 and an SG up to 3.00. Walrus ivory can only be processed and sold by the Inuit of North America and Greenland.Currently the Canadian Department of Fisheries and Oceans restricts the export of narwhal tusks but the Inuit traders are challenging the ban in court. The United States restricts the import of walrus and narwal ivory. More information about the ivory ban can be found at http://www.cites.org/.
Ivory chemistry & crystallographyChemicalNamecalcium hydroxyl phosphateChemicalFormulaDentine from teeth or modified teeth of mammals such as elephant, mammoth, hippopotamus, warthog, narwal or walrusSynthesisCrystalSystemNAChemistryClassificationOrganicNatureNaturalCrystallinityAmorphousChemistryComments
Ivory optical propertiesTransparencyTranslucent - OpaqueDispersionOpticalCommentsRefractiveIndex1.535-1.54BirefringenceOpticCharacterOpticSignPolariscopeReactionAggregate (AGG)FluorescenceSWUV: weak to moderate bluish white or violet blue
LWUV: weak to strong bluish white or violet blueCCFReactionPleochroismNone
Ivory characteristic physical propertiesHardness2.2-2.8CharacteristicCommentsStreakWhiteSpecificGravity1.7-2ToughnessFairInclusionsElephant and mammoth ivory will have wavy or intersecting curved lines in a v shaped pattern called engine turning effect. Mammoth or Moscow ivory tends to have more cracks than modern ivory. Walrus ivory or sea ivory is oval in cross section and the center has a rough bumpy appearance. Whale ivory comes from the teeth of sperm whales and can be found in antique Inuit carvings and scrimshaw. Narwhal ivory is hollow in the middle and tree-ring like growth patterns and a right to left spiral pattern.LusterGreasyStabilityFractureSplinteryCleavageNone