Lapis Lazuli
Lazurite-rich rock (Lapis Lazuli) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Isometric (Cubic), however usually occurs in massive or granular forms rather than distinct crystals
Mineral Group
Silicates (Sodalite group, Tectosilicate subgroup)
Chemical Formula
(Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2
Formation Process
Metamorphic; typically forms in contact metamorphism zones through the hydrothermal alteration of limestone or marble
About This Crystal
Deep celestial blue to ultramarine color with a greasy to vitreous luster. Typically opaque with a granular texture; often contains brassy yellow pyrite inclusions and white calcite veining
Physical Characteristics
Color: Royal blue; Streak: Light blue; Cleavage: Poor/indistinct; Fracture: Uneven to conchoidal; Specific Gravity: 2.7–2.9; Fluorescence: Often dull orange or pink under LWUV due to calcite
Optical Properties
Refractive Index: Approx. 1.50 (aggregate); Isotropic; No birefringence or pleochroism due to its rock-like aggregate nature
Hardness & Durability
Origin Region
Sar-e-Sang, Badakhshan Province, Afghanistan; also found in Chile, Russia, and Myanmar
Hardness & Durability
Mohs Hardness: 5.0–5.5; Fair toughness; sensitive to pressure and high temperatures; porous material
Care & Maintenance
Avoid ultrasonic cleaners and steam; clean with warm soapy water and a soft cloth; avoid acids and harsh chemicals; store separately to prevent scratching
Rarity & Value
Uncommon in high grades; value is determined by intense blue color (absence of gray or white) and a slight dusting of pyrite; Afghan material is top tier
Special Characteristics
Presence of Pyrite 'gold' flecks is a diagnostic feature; may be dyed or impregnated with wax/resin to improve color and stability
Lore & History
Used for over 6,000 years; highly prized by Ancient Egyptians for jewelry and amulets; traditionally associated with royalty, wisdom, and the Throat Chakra