Lapis Lazuli
Lapis Lazuli (Rock, predominantly Lazurite with Calcite and Pyrite) · Decorative Stone and Semi-Precious Gemstone
Crystal System
Cubic (mineral components form in cubic/isometric systems; typically found massive)
Mineral Group
Silicate group, specifically a feldspathoid of the sodalite group
Chemical Formula
(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2 (Lazurite component)
Formation Process
Metamorphic, specifically formed by contact metamorphism of limestone into skarn, typically at moderate to high temperatures
About This Crystal
This is a polished, tumbled specimen of a deep indigo to royal blue color, characteristic of high-quality lapis lazuli. The surface is smooth and shiny with a vitreous to greasy luster, reflecting light brightly. There are subtle hints of whitish calcite and tiny metallic pyrite flecks visible as faint specks on the surface.
Physical Characteristics
Deep blue body color with white calcite and golden pyrite inclusions; streak is light blue; cleavage is indistinct; fracture is uneven to conchoidal; specific gravity is approximately 2.7 to 2.9; tenacity is brittle
Optical Properties
Refractive index is around 1.50; aggregate structure means it is generally considered as having a pseudo-isotropic optical character; typically opaque with no pleochroism
Hardness & Durability
Origin Region
Notable sources include Badakhshan province in Afghanistan, Chile, Russia, and the United States
Hardness & Durability
Mohs hardness is 5 to 5.5, making it relatively soft compared to quartz; moderate toughness but sensitive to acids, harsh chemicals, and excessive heat; suitable for careful jewelry use like pendants and earrings
Care & Maintenance
Clean with a soft, damp cloth and mild soapy water; avoid ultrasonic cleaners, steam, acids, and harsh detergents; store separately in a soft pouch to prevent scratching by harder gemstones
Rarity & Value
Fairly common globally, but high-grade deep blue material with minimal calcite and attractive pyrite is valued higher; price ranges from inexpensive tumbled stones to moderate costs for high-grade cabochons and carvings; treatments can include dyeing or stabilization
Special Characteristics
Often features sparkling brassy-yellow pyrite inclusions that resemble starry night skies, which are highly prized by collectors
Lore & History
Historically used in ancient Mesopotamia, Egypt, and Persia for royal jewelry, amulets, and famously ground into ultramarine pigment for Renaissance paintings; traditionally associated with wisdom, truth, and the third eye chakra in modern crystal healing