Description Cuprous Sulfide, 99.5% (Metals Basis), Powder -200 mesh, 50g For Research & Development Not for drug, human, animal, or food use Certificate of Analysis:Appearance (Color) BlackAppearance (Form) Powder Purity (by Metals Basis) 99.5% Purity (by complexometric, as Cu) 76.30-83.4% Particle Size (mesh) -200 ICP Analysis Confirms Cu and S component CAS: 22205-45-4 FORMULA: Cu2S