Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
cubiccommonMetamorphic rock (composed of silicates, carbonates, and sulfides)
Lapis Lazuli
A rock composed primarily of lazurite ((Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]), calcite (CaCO3), and pyrite (FeS2).
A deep blue metamorphic rock characterized by its intense blue lazurite, often interspersed with white calcite veins and golden pyrite specks.
Lapis Lazuli Physical Properties
Mohs Hardness
5Crystal System
cubicLuster
vitreousStreak Color
Light blueCleavage
Imperfect (lazurite) to perfect rhombohedral (calcite)Fracture
Uneven to conchoidalSpecific Gravity
2.75Colors
deep blue, white, golden yellowTransparency
Opaque to translucentType Locality
Sar-e-Sang Deposit, Hindu-Kush Mountains, AfghanistanMineral Group
Metamorphic rock (composed of silicates, carbonates, and sulfides)Uses
jewelry, ornamental objects, pigmentAssociated Minerals
lazurite, calcite, pyriteRarity
commonGeological Context
Lapis lazuli is a contact metamorphic rock formed from limestone or marble through metasomatism, typically found in crystalline marbles associated with igneous intrusions. The Afghan deposits are Precambrian in age.
