Lapis Lazuli

Hardness: 5-5.5 (Mohs scale); Color: Intense blue, often with golden (pyrite) and white (calcite) inclusions; Luster: Dull to greasy; Crystal Structure: Usually massive, no distinct crystals visible; Cleavage: Indistinct; Specific Gravity: 2.7-2.9

Formed through contact metamorphism in crystalline limestone, often with associated minerals like calcite, pyrite, and sometimes diopside or sodalite. It is typically found in marble or as primary deposits in crystalline limestone. Geological age varies depending on the deposit, but many historical sources come from ancient metamorphic belts.

Prized as an ornamental gemstone and decorative material for millennia. Used in jewelry (beads, cabochons), carvings, sculptures, and inlays. Historically, powdered lapis lazuli was processed to create ultramarine pigment, highly valued by artists.

Lapis lazuli means 'blue stone' in Latin and Persian. It has been mined in Afghanistan for over 6,000 years, making it one of the oldest known gemstone materials. The finest lapis lazuli comes from Afghanistan and is characterized by its deep, uniform blue color with minimal calcite and evenly distributed pyrite flecks. The presence of pyrite was often considered desirable, resembling stars in a night sky.

Identify in the field by its distinctive deep blue color, often with brassy gold flecks of pyrite and white streaks or patches of calcite. It is typically found in metamorphic environments, particularly in marble deposits. The most significant deposits are in Afghanistan (Badakhshan province), but it is also found in Russia (Lake Baikal area), Chile (Ojos de Agua), and smaller quantities in Italy, Argentina, and the USA (California and Colorado). Collectors value specimens with an intense, even blue color.