Technical details: A) refractive index: 2.20+/-0.02 B) round ratio: less 10% C) opacity: less 5% D) specific gravity: 4.5+/-0.01 E) size: no. Mesh 1 160-200 2 200-250 3 250-300 4 300-350 5 350-400 6 400-450 Packing: 25kgs/iron drum Min order quantity: 200kgs Packing: 25kgs/iron drum