metamorphic
Lapis Lazuli
Lapis Lazuli (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
Hardness: 5-5.5 (Mohs scale), Color: Deep blue with gold pyrite flecks and white calcite veins, Luster: Vitreous to greasy, Crystal structure: Aggregated polycrystalline rock, Cleavage: None, Specific gravity: 2.7–2.9
- Hardness
- 5-5
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-5.5 (Mohs scale), Color: Deep blue with gold pyrite flecks and white calcite veins, Luster: Vitreous to greasy, Crystal structure: Aggregated polycrystalline rock, Cleavage: None, Specific gravity: 2.7–2.9
Formation & geological history
Formed via contact metamorphism when limestone or marble is altered by hydrothermal activity. Majority of specimens originate from the Mesozoic or Paleozoic eras. Primary deposits found in Afghanistan, Chile, and Russia.
Uses & applications
Extensively used in fine jewelry, decorative carvings, and inlay work. Historically ground into pigment for ultramarine paint for Renaissance art. Highly valued by collectors for intense blue saturation.
Geological facts
Lapis lazuli was used for the funeral mask of Tutankhamun and was prized across ancient Mesopotamia, Egypt, and Rome. It is actually a rock composed primarily of the mineral lazurite.
Field identification & locations
Field identification involves searching for the characteristic 'ultramarine blue' color often accompanied by metallic pyrite 'sparkles.' Found in hydrothermal metamorphic zones in marble host rock. Use a streak test (produces light blue) to differentiate from sodalite.
More like this
