Lapis Lazuli (Low Grade/Denim Lapis)
Lapis Lazuli (A rock primarily composed of Lazurite, Calcite, and Pyrite) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Isometric (for Lazurite components); massive or granular habit as a rock aggregate.
Mineral Group
Silicates (specifically Tectosilicates / Feldspathoid group members)
Chemical Formula
(Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2 (Lazurite) with CaCO3 (Calcite) and FeS2 (Pyrite)
Formation Process
Metamorphic; typically forms through contact metamorphism of limestone or marble.
About This Crystal
An opaque blue rock with a vitreous to greasy luster. This specific specimen shows a 'denim' blue color due to high white Calcite content and mottled grey-brown host rock inclusions.
Physical Characteristics
Color: mottled blue and white/grey. Streak: light blue. Cleavage: none (granular aggregate). Fracture: uneven to conchoidal. Specific Gravity: 2.7–2.9. Fluorescence: often displays orange/pink Calcite fluorescence under Long Wave UV.
Optical Properties
Opaque rock aggregate; refractive index typically around 1.50 (aggregate). Not applicable for single crystal phenonmena.
Hardness & Durability
Origin Region
Sar-e-Sang, Afghanistan (primary source); also Chile, Russia, Myanmar, and USA.
Hardness & Durability
Mohs hardness 5 to 5.5. Fair toughness, but sensitive to pressure and acids. Moderate wearability for jewelry.
Care & Maintenance
Avoid ultrasonic cleaners, steam, and harsh chemicals. Clean with warm soapy water and a soft cloth. Do not soak, as the stone is porous.
Rarity & Value
Common (low grade). Value is determined by the intensity of the blue color and absence of white calcite. This specimen is lower-tier decorative grade.
Special Characteristics
Displays a characteristic 'mottled' appearance. Higher quality specimens usually feature golden Pyrite flecks, which appear absent or minimal here.
Lore & History
Historically used in ancient Egypt for jewelry and ground into ultramarine pigment. Traditionally associated with truth, wisdom, and the Throat and Third Eye chakras.