Scientific Name: Lazurite
Group: Silicates – tectosilicates
Chemical composition: Na3Ca(Al3Si3O12)S
Colors: Various intense shades of blue.
Hardness: 5 to 5.5
Formation: Cubic crystals
Principal Sources: Afghanistan, Italy, Argentina, US, Tajikistan.
Special Notes: The best quality is intense dark blue, with patches of white calcite and yellow pyrite. Lapis was used as a gemstone for thousands of years by Egyptians. Powdered lapis was used to make the pigment ultramarine.