Ametrine Gemstone & Information | Gemopedia by JTV | Gemopedia™
Ametrine is a bi-color quartz variety that, as its name suggests, is a unique combination of amethyst and citrine within a single crystal. How the gem forms is still a bit of a mystery, but the differences in color are believed to be the result of the presence of iron in different states of oxidation from natural heating. Combining the golden sunburst of citrine with the violet sunset of amethyst, this naturally colored gem is commercially mined at a single source: the remote Anah mine in Bolivia and is shrouded in fascinating local legends and lore.
Bicolored Combination Of Purple, Yellow
Ametrine classificationCommonNameAmetrineSpeciesQuartzVarietyAmetrineColorsBicolored Combination Of Purple, YellowAlternateNamesTrystine, Bolivianite, Amethyst-Citrine, Citrine-Amethyst, Golden AmethystGemstoneGroupsKeySeparationsAmetrine's appearance is distinctive and otherwise the key quartz indicators will be present (refractive index, birefringence, optic character and optic figure). A bull's-eye optic figure is determinative for quartz. Might also show Airy's spiral.ClassificationCommentsStones might be piezoelectric: able to generate electricity produced by mechanical pressure,Pyroelectricity: development of opposite charges at the ends of the axis due to change in temperature and triboluminescent: luminescence produced by friction.
Ametrine chemistry & crystallographyChemicalNamesilicon dioxide (aka silica)ChemicalFormulaSiO2SynthesisCrystalSystemTrigonalChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Ametrine optical propertiesTransparencyTransparent - TranslucentDispersionStrength: weak fire Value: 0.013OpticalCommentsRefractiveIndex1.544-1.553
Tolerance:very constantBirefringence0.009-0.009OpticCharacterUniaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert
LWUV: InertCCFReactionPleochroismDichroic, weak yellow-orange and purple
Ametrine characteristic physical propertiesHardness7CharacteristicCommentsStreakWhiteSpecificGravity2.64-2.69 Range:0.03/-0.02 Typical:2.66ToughnessGoodInclusionsAmetrine is a type II clarity stone. Color zoning in stones is often present in the form of "soap scum", "tiger stripes" or "zebra stripes", crystals, negative crystals, liquid inclusions, two-phase inclusions, partially-healed fractures, hematite needles.LusterVitreousStabilityGoodFractureConchoidalCleavageNone