Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
cubicuncommonMetamorphic Rock (composed primarily of lazurite, a tectosilicate)
Lapis Lazuli
(Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)] (primarily lazurite, a component mineral)
A deep blue metamorphic rock, often characterized by its intense blue color, white calcite veins, and golden pyrite flecks. The image shows a deep blue specimen with visible whitish inclusions and brassy gold specks.
Lapis Lazuli Physical Properties
Mohs Hardness
5Crystal System
cubicLuster
vitreousStreak Color
light blueCleavage
imperfect (for lazurite, generally absent in the rock)Fracture
uneven to conchoidalSpecific Gravity
2.7Colors
deep blue, white, goldenTransparency
opaqueType Locality
Sar-e-Sang Deposit, Hindu-Kush Mountains, AfghanistanMineral Group
Metamorphic Rock (composed primarily of lazurite, a tectosilicate)Uses
jewelry, ornamental objects, pigment (ultramarine)Associated Minerals
lazurite, calcite, pyriteRarity
uncommonGeological Context
Lapis lazuli is a lazuritic metamorphite, formed by contact metamorphism of limestone in the presence of sulfur-rich fluids. The specimen is from the Precambrian Sakhi Formation in Afghanistan.
