Lapis Lazuli Gemstone & Information | Gemopedia by JTV | Gemopedia™
Discover the mystical allure of rich, royal blue and sparkling golden specks found in lapis lazuli. Very few gems have such a long and storied history as lapis lazuli. Along with carnelian, it is the oldest known gemstones to be appreciated and worn as adornment. When lapis lazuli was first introduced to Europe, it was called ultramarine, meaning "beyond the sea." The gem was ground to a powder for use as early eye shadow, and as pigment for early oil paints. Today, this rich blue gem still retains the allure that first captivated humans thousands of years ago.
Medium To Dark, Slightly Greenish Blue To Violetish Blue
Lapis-lazuli classificationCommonNameLapis LazuliSpeciesNAVarietyColorsMedium To Dark, Slightly Greenish Blue To Violetish BlueAlternateNamesLapisGemstoneGroupsKeySeparationsApperance, RI, magnification and possibly fluorescenceClassificationCommentsSome areas of the stone might have a RI of 1.67 due to calcite inclusions. Lapis lazuli is a mixture of lazurite, calcite and pyrite.
Lapis-lazuli chemistry & crystallographyChemicalNamesodium calcium aluminum silicateChemicalFormula(Na,Ca)8[(SiO4,S,Cl)2I(AlSi)4]6SynthesisCrystalSystemNAChemistryClassificationSilicateNatureNaturalCrystallinityPolycrystallineChemistryComments
Lapis-lazuli optical propertiesTransparencySemitranslucent - OpaqueDispersionStrength: noneOpticalCommentsRefractiveIndex1.5BirefringenceOpticCharacterNAOpticSignNAPolariscopeReactionAggregate (AGG)FluorescenceSWUV: weak to moderate green to yellowish green
LWUV: InertCCFReactiondull reddish brownPleochroismNone
Lapis-lazuli characteristic physical propertiesHardness5-6CharacteristicCommentsStreakWhite To Light BlueSpecificGravity2.25-3 Typical:2.75ToughnessFairInclusionsLapis lazuli commonly contains pyrite and white calcite. The pyrite inclusions in natural stones are randomly scattered throughout the stone and have irregular outlines that are surrounded by darker blue rings.LusterVitreousStabilityFractureGranular, UnevenCleavageNone