Lapis Lazuli (in Matrix)
Lapis Lazuli (a rock composed primarily of Lazurite, Calcite, and Pyrite) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric) for lazurite crystals; typically occurs in massive, granular, or compact habits.
Mineral Group
Silicates; Sodalite group (Tectosilicates)
Chemical Formula
(Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2 [Lazurite component]
Formation Process
Metamorphic; typically forms through contact metamorphism of limestone or marble.
About This Crystal
Deep celestial blue patches of lazurite embedded within a white to greyish marble/calcite matrix. The blue areas show a dull to vitreous luster, while the matrix appears grainy and opaque.
Physical Characteristics
Color: Ultramarine blue with white (calcite) and metallic gold (pyrite). Streak: Light blue. Cleavage: Poor/None. Fracture: Uneven/Conchoidal. Specific Gravity: 2.7 to 2.9 (variable due to matrix).
Optical Properties
Refractive Index: ~1.50 (aggregate). Opaque. No pleochroism. May show white or orange fluorescence under LWUV due to calcite/sodalite content.
Hardness & Durability
Origin Region
Sar-e-Sang, Badakhshan Province, Afghanistan (Primary source); also Chile, Russia, and Myanmar.
Hardness & Durability
Mohs Hardness: 5 to 5.5. Toughness: Fair to Poor. Sensitive to pressure and high temperatures. Suitable for beads/cabochons but requires protection.
Care & Maintenance
Avoid ultrasonic and steam cleaners. Clean with warm soapy water and a soft cloth. Guard against acids and household chemicals which can dissolve the calcite matrix.
Rarity & Value
Common to Uncommon. Value is determined by the intensity of the blue (lazurite) vs the amount of white matrix/calcite. High-grade specimens have minimal matrix.
Special Characteristics
Often contains micro-inclusions of brassy yellow Pyrite ('fool's gold'), giving it a starry appearance, though less visible in this specific matrix-heavy sample.
Lore & History
Used since the 7th millennium BC. Famous for the funeral mask of Tutankhamun and as the source of 'ultramarine' pigment in Renaissance art. Traditionally associated with the Third Eye chakra, wisdom, and truth.