Appearance Flowing Mgso4 60%-82% Mgo 17%-27% Ph(5w/v%sol) 5-6.5 Ferron(Fe) 0.002% max Chlorid(Cl) 0.005% max Heavy metal (Pb) 0.001 %max Arsenic(As) 0.0002% max Water insoluble 5%-22% Size (mm) 2-4mm