Description CAS#: 21908-53-2 | Formula: HgO | Specifications: Assay 99.0 % - Min, Insoluble in dil. HCl (%) 0.03 %, Residue after reduction (%) 0.05 %, Chloride 0.025 %, Sulfate 0.01 %, Nitrogen compounds (%) 0.005 %, Iron 0.003 %