Pakistan Aquamarine 'A' Grade Rough - 50 Carat Lot | Lapidary for Cabbing, Tumbling, Wire Wrapping, Reiki Scientific Group: Silicate: Beryl Scientific Formula: Be3Al2Si6O18 Specific Gravity: 2.63 - 2.78 Mohs Hardness: 7.5 - 8.0 Refractive Index: 1.562 - 1.602