Lazurite
Image: Photographer: Henk Caspers/Naturalis (CC BY-SA 3.0)
Mineral NameLazurite
Chemical Formula(Na,Ca)8(Al6Si6O24)(SO4,S,Cl)2
Mohs Hardness5
Lustervitreous
Streak Colorlight blue
Cleavageimperfect on {110}
Fractureuneven
Specific Gravity2.4
Colorsazure-blue, violet-blue, greenish-blue
Transparencytranslucent
Type LocalitySar-e-Sang, Badakhshan, Afghanistan
Mineral GroupSilicates
Usesgemstone, pigment, ornamental
Associated Mineralscalcite, pyrite, diopside
Rarityuncommon
Description
A vibrant, intense blue mineral, often found in massive form as a component of the rock Lapis Lazuli, frequently intergrown with white calcite and golden pyrite.
Geological Context
Lazurite typically forms in metamorphosed limestones or dolomites through contact metamorphism, where it replaces carbonate minerals in the presence of sulfur-rich fluids.
