Appearance and properties: white shiny square crystal, specific gravity 3.59-3.95. Highly volatile, the volatile condensate was white or pale yellow needles, without melting on evaporation, sublimation temperature of 315 ° C, the melting point of 340-350 ° C. Easily soluble in water generated selenite (H2SeO3),. 
 Main Uses: mainly used for manganese electrolytic additives used to drink black agent of the trace elements additives, iron and steel materials, but also for the oxidant, catalyst, chemical reagents.