Oregon Sunstone Gemstone & Information | Gemopedia by JTV | Gemopedia™
While feldspars are found throughout the world, they are rarely of gem quality. However, there is a very special feldspar variety known as sunstone found in south central Oregon. The Oregon sunstone is both gem grade and available in large enough sizes to yield cut stones for jewelry. The deposit is located in the region's rugged high desert where sunstone is embedded in ancient lava flows of an extinct volcano. As the lava weathers away or is broken up, Mother Nature releases the crystals for man to gather.
Pale Pinkish Orange, Pink, Reddish Orange, Red-Orange, Deep Red With Red, Green, Blue Adventurescence
Oregon-sunstone classificationCommonNameOregon SunstoneSpeciesLabradoriteVarietyOregon SunstoneColorsPale Pinkish Orange, Pink, Reddish Orange, Red-Orange, Deep Red With Red, Green, Blue AdventurescenceAlternateNamesAventurine FeldsparGemstoneGroupsFeldsparKeySeparationsRI, birefringence, optic character and magnification.ClassificationComments
Oregon-sunstone chemistry & crystallographyChemicalNamepotassium, sodium or calcium silicateChemicalFormulaNaAlSi3O8 or CaAl2SiO8SynthesisCrystalSystemTriclinicChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Oregon-sunstone optical propertiesTransparencyTranslucent - OpaqueDispersionStrength: noneOpticalCommentsRefractiveIndex1.563-1.572Birefringence0.009OpticCharacterBiaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV: Inert to moderate red
LWUV: Inert to moderate violetCCFReactionPleochroismDichroic, strong red and green
Oregon-sunstone characteristic physical propertiesHardness6CharacteristicCommentsStreakWhiteSpecificGravity2.67-2.72 Typical:2.67ToughnessPoorInclusionsOregon sunstone contain tiny orange or yellow copper platelets or hematite platelets and stones might display adventurescence. Parting is common in this material.LusterVitreousStabilityGoodFractureUneven, SplinteryCleavagePerfect, in two directions