Verdelite Gemstone & Information | Gemopedia by JTV | Gemopedia™
Verdelite refers to green tourmaline that does not contain chromium. Although green is a common color of tourmaline, not all greens are valued equally. Verdelite gems come in varying shades of green; some so saturated that direct light is necessary to see the body color. From lush grass-green to electric yellow-green to olive, and even bluish green, there is a verdelite gem to fit all tastes.
Dark Green, Yellowish Green, Blueish Green, Light Green, Light Brown
Verdelite classificationCommonNameVerdeliteSpeciesTourmalineVarietyVerdeliteColorsDark Green, Yellowish Green, Blueish Green, Light Green, Light BrownAlternateNamesVerdelithGemstoneGroupsKeySeparationsappearance, refractive index and high birefringence; then optic figure, pleochroism and specific gravityClassificationCommentsMisnomer: Emeraldite. Not all verdelite is elbaite tourmaline Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH). Pyroelectric: development of opposite charges at the ends of a tourmaline crystal due to change in temperature. Piezoelectric: development of opposite charges at the ends of a tourmaline crystal when placed under stress.
Verdelite chemistry & crystallographyChemicalNamecomplex boro-silicate of Al, Mg and FeChemicalFormulaNa(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)SynthesisCrystalSystemTrigonalChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Verdelite optical propertiesTransparencyTransparent - OpaqueDispersionStrength: moderate fire Value: 0.017OpticalCommentsRefractiveIndex1.624-1.644Birefringence0.014-0.04OpticCharacterUniaxialOpticSignNegativePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Variable
LWUV: VariableCCFReactionPleochroismDichroic, strong dark green and yellow-green
Verdelite characteristic physical propertiesHardness7-7.5CharacteristicCommentsStreakWhiteSpecificGravity3-3.26 Typical:3.06ToughnessGoodInclusionsVerdelite tourmaline is Type I clarity stone. Stones might contain liquid and gas inclusions that are long and thin, reflective gas-filled fractures and color zoning.LusterVitreousStabilityVery GoodFractureConchoidal, UnevenCleavagePoor, in two directions