Prasiolite Gemstone & Information | Gemopedia by JTV | Gemopedia™
A pastel dream, this variety of quartz boasts a beautiful soft green color. Sometimes called "green amethyst" or "lime citrine," prasiolite is rarely found in nature, so most material available on the market is produced by heating or irradiating amethyst or citrine. Prasiolite is an exciting gem in that it is readily available in large sizes with high transparency and great durability.
Green To Yellowish Green
Prasiolite classificationCommonNamePrasioliteSpeciesQuartzVarietyPrasioliteColorsGreen To Yellowish GreenAlternateNamesGreen Quartz, "Greened Amethyst"GemstoneGroupsKeySeparationsRefractive index, birefringence, optic character and optic figure. A bull's-eye optic figure is determinative for quartz. The presence of Brazil-law twinning is a means of separating amethyst from scapolite.ClassificationCommentsMisnomer: green amethyst. Green color is rarely found naturally and most are irradiated and/or heat treated.
Prasiolite chemistry & crystallographyChemicalNamesilicon dioxide (aka silica)ChemicalFormulaSiO2SynthesisCrystalSystemTrigonalChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Prasiolite optical propertiesTransparencyTransparent - TranslucentDispersionStrength: weak fire Value: 0.013OpticalCommentsRefractiveIndex1.544-1.553
Tolerance:very constantBirefringence0.009OpticCharacterUniaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert
LWUV: InertCCFReactionPleochroismDichroic, unobservable or weak, varying shades of body color
Prasiolite characteristic physical propertiesHardness7CharacteristicCommentsStreakWhiteSpecificGravity2.64-2.69 Typical:2.66ToughnessGoodInclusionsPrasiolite is a type II clarity stone. Stones may contain crystals, negative crystals, liquid inclusions, two-phase inclusions and partially-healed fractures.LusterVitreousStabilityGoodFractureConchoidalCleavageNone