Biological calcium carbonate (Oyster shell powder) Main component: CaCO 3 Appearance: White powder Product specification: Item QB1413-99 CaCO 3 (dry base) e % 97.6 Loss on drying d % 1.0 Acid-insoluble substances d % 0.30 Barium d % 0.03 Arsenic d mg/kg 3 Heavy metals d mg/kg 10 Cadmium e mg/kg 0.2 Fineness (mesh) e 180 Packaging and storage: 25 kg / paper plastic complex bag.