... , super workmanship Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula: (Na,Ca)8[(S,Cl,SO4,OH)2 ... although well formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli. Lazurite is ... pyrite. Lazurite is a product of contact metamorphism of limestone and typically is associated with calcite, pyrite, diopside, humite, forsterite, ...