Dark red crystal, used in wood preservative, medicine, catalyst, pigment, oxidizer, glass coloring, fabric mordant manufacturing. Raw materials for making oxidation catalysts Crystal Chromic Acid (1) CrO3 ω/% ≥99.8 (2) Na+≤ 0.08 (3) Cl-≤ 0.004 (4) So42-ω/%≤ 0.003 (5) Insoluble ω/%≤ 0.001