Silicates & Quartz
Lazurite
What it is
The intense blue mineral that gives lapis lazuli its famous color. Lazurite is a sulfur-bearing sodalite-group mineral. The gold flecks in lapis are pyrite, and the white patches are calcite.
How it forms
Forms when limestone is contact-metamorphosed by nearby magma intrusions. The sulfur that creates the blue color comes from sulfur-bearing fluids during metamorphism.
(Na,Ca)₈(AlSiO₄)₆(SO₄,S,Cl)₂
