metamorphic
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
Hardness: 5-5.5 on Mohs scale. Color: Vivid royal blue (ultramarine). Luster: Dull to greasy, can reach vitreous when polished. Crystal structure: Isometric (Lazurite). Cleavage: Indistinct. Specific gravity: 2.7 to 2.9.
- Hardness
- 5-5
- Color
- Vivid royal blue (ultramarine)
- Luster
- Dull to greasy, can reach vitreous when polished
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-5.5 on Mohs scale. Color: Vivid royal blue (ultramarine). Luster: Dull to greasy, can reach vitreous when polished. Crystal structure: Isometric (Lazurite). Cleavage: Indistinct. Specific gravity: 2.7 to 2.9.
Formation & geological history
Formed through contact metamorphism, where heat from igneous intrusions alters limestone or marble. The most famous deposits in Afghanistan date back over 6,000 years to the Precambrian era.
Uses & applications
Used primarily in jewelry (cabochons, beads), decorative carvings, and historically as a pigment for ultramarine paint used by Renaissance artists.
Geological facts
Lapis Lazuli was highly prized by Ancient Egyptians for amulets and funeral masks, most notably the mask of Tutankhamun. It is technically a rock, not a mineral, because it is composed of multiple minerals: Lazurite, Pyrite, and Calcite.
Field identification & locations
Field identification is based on the intense 'ultramarine' blue color and the presence of gold-colored pyrite specks or white calcite veins. Major deposits are found in Afghanistan (Sar-e-Sang), Chile, Russia, and the USA (California and Colorado).
More like this
