Gele Opaal 5.11 CT. Size: 10.2x14.2x6.9 mm Oval Cut Shape: Oval Cut Color: Yellow Clarity: VVS Luster: Fire Flash Origin: Australia Hardness: 5.5 - 6.5 Specific Gravity: 1.42 - 2.25 Refractive Index: 1.37 - 1.47 Chemical Composition: SiO2-nH2O, Hydrated Silicon Dioxide Crystal Structure: N/A Treatment: None