Lapis Lazuli
Lazurite-rich metamorphic rock · Semi-Precious Gemstone / Decorative Stone
Crystal System
Isometric (for constituent lazurite crystals); typically occurs in massive, aggregate forms
Mineral Group
Sodalite group (Silicates / Tectosilicates)
Chemical Formula
(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2 with Pyrite (FeS2) and Calcite (CaCO3)
Formation Process
Metamorphic; specifically contact metamorphism of limestone or marble
About This Crystal
An opaque, deep royal blue rock with a vitreous to greasy luster. It typically features speckles of golden Pyrite and white veins or patches of Calcite.
Physical Characteristics
Color: Deep blue with gold/white inclusions; Streak: Light blue; Cleavage: None/Indistinct; Fracture: Uneven to conchoidal; Specific Gravity: 2.7–2.9; Fluorescence: Often inert but Calcite inclusions may glow pink/orange.
Optical Properties
Refractive Index: Approx. 1.50 (aggregate); Singly refractive; No pleochroism due to opacity; No dispersion.
Hardness & Durability
Origin Region
Sar-e-Sang, Badakhshan Province, Afghanistan (primary source); also Chile, Russia, and Canada
Hardness & Durability
Mohs Hardness: 5–6; Toughness: Fair to Poor; Sensitivity: Highly sensitive to acids, high heat, and pressure; Wearability: Moderate (better for pendants than rings).
Care & Maintenance
Clean only with warm soapy water and a soft cloth; avoid ultrasonic cleaners, steam, and acidic chemicals. Store separately to prevent scratching from harder stones.
Rarity & Value
Common to Uncommon; Value is highest for intense 'Ultramarine' blue with minimal Calcite and evenly distributed Pyrite. Often dyed or impregnated with wax/resin.
Special Characteristics
Natural composite rock; characterized by the presence of golden Pyrite inclusions ('fool's gold') which confirm its authenticity.
Lore & History
Highly prized in Ancient Egypt for jewelry and amulets (e.g., King Tut's mask); historically ground into 'Ultramarine' pigment for Renaissance painters. Traditionally associated with the Throat Chakra, truth, and wisdom.