Lapis lazuli (hardness: 5-5.5 Mohs)
A rock composed mainly of the mineral lazurite with variable amounts of pyrite (brassy flecks) and white calcite
Specific gravity: 2.7-2.9
Diamond Star of Sierra Leone.
Deep blue, azure blue, greenish blue (bluish color with flecks of white and gold)
Opal (hardness: 5.5-6.5 Mohs)
Hydrated silica
Specific gravity: 1.98-2.25
White opal: Opaque, porcelain-like white material; colors resemble flashes or speckles