Natrolite Gemstone & Information | Gemopedia by JTV | Gemopedia™
Natrolite is a zeolite mineral named for the Greek word natron meaning "soda" due to the presence of sodium in the stone. Its range of colors include yellow, gray, brown to colorless. Occasionally, it is found in pale yellow to red hues. Crystals often grow in long, needle-like formations, and are especially prized by specimen collectors.
White, Colorless, Reddish, Greenish, Brownish, Yellowish.
Natrolite classificationCommonNameNatroliteSpeciesNatroliteVarietyColorsWhite, Colorless, Reddish, Greenish, Brownish, Yellowish.AlternateNamesGemstoneGroupsKeySeparationsRI, appearance and possibly fluorescence.ClassificationCommentsSometimes pyroelectric: development of opposite charges at the ends of the crystal due to change in temperature. Sometimes piezoelectric: development of opposite charges at the ends of the crystal when placed under stress.
Natrolite chemistry & crystallographyChemicalNamehydrated sodium aluminum silicateChemicalFormulaNa2[Al2Si3O10].2H2OSynthesisCrystalSystemOrthorhombicChemistryClassificationSilicateNatureNaturalCrystallinityCrystalline to AggregateChemistryComments
Natrolite optical propertiesTransparencyTransparent - OpaqueDispersionStrength: weak fire Value: 0.005OpticalCommentsRefractiveIndex1.48-1.493Birefringence0.012-0.013OpticCharacterBiaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert to strong green
LWUV: Inert to weak greenish whiteCCFReactionPleochroismUnobservable
Natrolite characteristic physical propertiesHardness5-5.5CharacteristicCommentsStreakWhiteSpecificGravity2.2-2.26ToughnessPoorInclusionsNatrolite is usually found as a fibrous aggregate. Stones might have yellowish brown acmite inclusions that appear rod-like.LusterVitreousStabilityFractureUnevenCleavagePerfect, in one direction