Lapis Lazuli

Hardness: 5-5.5 on Mohs scale. Color: Intense blue, often with white calcite streaks and brassy pyrite flecks. Luster: Dull to greasy. Crystal Structure: Typically massive, granular, or compact; individual crystals are rare. Cleavage: None. Specific Gravity: 2.7-2.9.

Lapis Lazuli is a metamorphic rock formed by contact metamorphism of limestone or marble. It forms at high temperatures and moderate pressures, typically in areas of calcium-rich rock that have been altered by hot fluids. The geological age of common deposits varies, with some being millions of years old. The distinctive blue color comes from the lazurite mineral, while calcite provides white streaks and pyrite creates golden specks.

Historically, Lapis Lazuli was highly prized for its intense blue color and difficult-to-synthesize pigment. It was used extensively in ancient Egypt, Mesopotamia, and the Roman Empire for jewelry, ornaments, carvings, and architectural decoration. Its ground form, ultramarine, was the most expensive blue pigment for centuries, used in frescoes and oil paintings by masters like Michelangelo and Vermeer. Today, it is primarily used for jewelry (cabochons, beads), small sculptures, inlays, and decorative items. Its collecting value is moderate, with well-formed, intense blue pieces fetching higher prices.

Lapis Lazuli has been mined for over 6,000 years in Afghanistan, making it one of the oldest gemstones known to man. Its name is derived from the Latin 'lapis' (stone) and the Persian 'lazhuward' (blue). The famous death mask of Tutankhamun is richly inlaid with Lapis Lazuli.

In the field, Lapis Lazuli can be identified by its distinctive intense blue color, often mottled with white (calcite) and speckled with metallic gold (pyrite). It typically has a dull to greasy luster. It feels relatively dense. Common locations include the Sar-e-Sang mines in Afghanistan (main source), Russia (Slyudyanka River, Lake Baikal), Chile (Ovalle), and smaller deposits in the United States (Colorado) and Canada. For collectors, look for vibrant, deep blue specimens with well-distributed pyrite flecks and minimal white calcite. Polished pieces best showcase its beauty.