Lapis Lazuli
Image: Nicola Quirico (CC BY-SA 4.0)
Mineral NameLapis Lazuli
Chemical Formula(Na,Ca)8(Al6Si6O24)(S,SO4,Cl)2
Mohs Hardness5
Crystal Systemcubic
Streak Colorlight blue
Cleavageimperfect
Fractureuneven to conchoidal
Specific Gravity2.75
Colorsdeep blue, golden, white
Transparencyopaque
Type LocalityBadakhshan, Afghanistan
Mineral GroupTectosilicates
Usesjewelry, ornamental objects, pigment
Associated Mineralspyrite, calcite, sodalite
Rarityuncommon
Description
A vibrant, deep blue metamorphic rock, often speckled with sparkling golden pyrite inclusions and sometimes streaked with white calcite, giving it a distinctive appearance.
Geological Context
Lapis Lazuli forms through contact metamorphism of limestones or dolomites, typically in association with igneous intrusions where sulfur-rich fluids interact with carbonate rocks.
