Lazurite Afgan Second class

Lazurite (Lapis Lazuli) Afgan Second class natural pigment powder. Lazurite is a relatively rare semi-precious stone that has been prized for its deep blue color since ancient times. It has been mined in Afghanistan for over 8000 years, and in Russia since the 19th century.  Second class Lazurite differs from other types in its lighter blue color. The reason is more quartz that contains in stones, which are used in its production. Chemical formula: Na6Ca2(AlSiO4)6(SO4,S,Cl)2 Chemical description: Mineral. Sodalite group frame silicate. Alkali resistance: 5 Lime Resistance: 5 Acid resistance: 5 Light-resistance: 8 Suitability Acrylic, Fresco, Oil, Tempera, Watercolor / Gouache Color: light blue to deep blue Glazing Color Index: PB 29