blue-green orthorhombic crystal，Soluble in water, soluble in alcohol, acetone, ethyl acetate, ammonia. Slightly soluble in ether. Yi deliquescence. Weathering easily in dry air。

Used to increase the copper ion plating tank additives, organic and inorganic reactions as a catalyst, the oil industry as a deodorizer, desulfurization and purification agent, the mordant dyeing, aniline dyes oxidants. Also used for metal smelting, glass and ceramics colorant, fish feed additives. Anhydrous brown-yellow powder. Are hygroscopic