Lapis Lazuli
From The Gemology Project
Lapis Lazuli | |
---|---|
Chemical composition | rock consisting of lazurite, hauyne, calcite and pyrite |
Habit | aggregate |
Fracture | uneven |
Hardness | 5.5 |
Refractive index | 1.500 - 1.670 |
Specific gravity | 2.50 - 3.00 |
Lustre | resinous to vitreous |
Enhancements
Common enhancements to lapis lazuli:
- Fracture filling - wax (with dye or withou) - conceal cracks and fractures and to improve luster
- Dye - color staining - to produce evenly colored material