Description Cuprous Sulfide, 99.5% (Metals Basis), Powder -200 mesh, 250g For Research & Development Not for drug, human, animal, or food use Certificate of Analysis:Appearance (Color) BlackAppearance (Form) PowderPurity (by Metals Basis) 99.5%Purity (by complexometric, as Cu) 76.30-83.4%Particle Size (mesh) -200ICP Analysis Confirms Cu and S component CAS: 22205-45-4 FORMULA: Cu2S