Chrysopraas (Imperial) 0.35 CT. 4 mm Antique Cushion Fine 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 www.hetsteenenhuis.com