Lapis Lazuli

Hardness: 5-5.5 on Mohs scale. Color: Intense azure blue to violet-blue, often with white calcite (visible as white streaks or patches) and brassy pyrite inclusions (visible as gold flecks). Luster: Dull to greasy. Crystal structure: Typically massive, granular, or compact; rarely forms dodecahedral crystals. Cleavage: Indistinct. Specific Gravity: 2.7-2.9.

Lapis Lazuli is a metamorphic rock formed by contact metamorphism of limestone or marble. It typically forms in close association with igneous intrusions in highly crystalline limestone or dolomite. The formation involves high temperatures and pressures that cause the original minerals to recrystallize and form new minerals. Its geological age varies depending on the deposit, but many significant deposits are hundreds of millions of years old.

Primarily used as a gemstone in jewelry, often cut into cabochons, beads, or carvings. It is also used for ornamental objects, sculptures, and inlay work. Historically, it was ground into a pigment called ultramarine, though synthetic versions are now more common for paint. It is also collected by mineral enthusiasts.

Lapis Lazuli has been prized since antiquity for its intense blue color. It was used extensively in ancient Egypt, Mesopotamia, and the Indus Valley Civilization for jewelry, ornaments, and inlays. Its name comes from Latin 'lapis' (stone) and Persian 'lazhward' (blue). The famous blue paint ultramarine was historically derived from ground lapis lazuli, making it one of the most expensive pigments.

Lapis Lazuli is most commonly found in Afghanistan (Badakhshan province), which has been the leading source for thousands of years. Other significant sources include Siberia (Russia), Chile, Pakistan, Canada, and the United States (Colorado). In the field, look for its distinctive deep blue color, often mottled with white calcite and speckled with golden pyrite. Its relatively low hardness (compared to quartz) means it can be scratched by a steel file. It does not typically form large, distinct crystals in common occurrences. The presence of these three minerals (blue lazurite, white calcite, and golden pyrite) together is a key identifier.