Chrysopraas (Imperial) Weight:± 0.30 CT. Size: 4 mm Shape: Round Cabochon Color: Apple Green Clarity: Transparent Luster: Good Origin: Australia Hardness: 6.0 - 7.0 Specific Gravity: 2.58 - 2.64 Refractive Index: 1.53 - 1.54 Chemical Composition: SiO2, Silicon Dioxide Crystal Structure: N/A Treatment: None