Species: Lapis Lazuli
Mohs Hardness: 5 to 5.5 out of 10
Color: Semi-translucent to opaque. Medium to dark slightly greenish blue to violetish blue. Could be mottled with different tones of blue with white calcite patches. May have metallic gold pyrite flecks.
RI: Vague readings around 1.500 and sometimes 1.670 due to calcite
Fluorescence: Weak to moderate green or yellowish green under SW. Calcite inclusions might fluoresce pink under LW.
SG: 2.75 (+/-0.25)