Appearance

Green to Blue-Green Crystals

［NiSO4·(NH4)2SO4·6H2O］Assay

≥ 98.0%

Insoluble matter in water    

≤ 0.005%

Chloride

≤ 0.001%

Iron 

≤ 0.0005%

Cobalt

≤ 0.01%

Zinc  

≤ 0.005%

Heavy metals（Pb）

≤ 0.002%

Substances not precipitated by ammonium sulfide( SO42-)

≤ 0.05%