Sanidine Gemstone & Information | Gemopedia by JTV | Gemopedia™

Sanidine is a potassium-rich feldspar which is related to amazonite (microcline) and orthoclase by its chemistry. Sanidine gems that display adularescence, a mystical internal glow, are called moonstone. Colorless to yellow and pale brown gems have been found in Germany, Mexico, and Madagascar.
Colors
Colorless, Pale Pink, Gray, White, Yellow
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Sanidine classification
CommonNameSanidineSpeciesOrthoclaseVarietySanidineColorsColorless, Pale Pink, Gray, White, YellowAlternateNamesGemstoneGroupsFeldsparKeySeparationsClassificationCommentsSandine is a monoclinic disordered orthoclase. Some stone show low levels of radioactivity. -
Sanidine chemistry & crystallography
ChemicalNameChemicalFormulaKAlSi3O8SynthesisCrystalSystemMonoclinicChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments -
Sanidine optical properties
TransparencyTransparent - TranslucentDispersionStrength: weak fire Value: 0.012OpticalCommentsRefractiveIndex1.518-1.531Birefringence0.003-0.007OpticCharacterBiaxialOpticSignNegativePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert to weak red-orange
LWUV: Inert to weak red-orangeCCFReactionPleochroismUnobservable -
Sanidine characteristic physical properties
Hardness6-6.5CharacteristicCommentsStreakWhiteSpecificGravityTypical:2.6ToughnessInclusionsLusterVitreousStabilityFractureConchoidal, UnevenCleavagePerfect, in two directions