Description : Very Light, white powder, odourless 15 gms. occupies about a 180 ml •dissolves in dilute acids with strong effervescence • Light Magnesium Carbonate contains the equivalent of not less than 40% magnesium oxide • Heavy Metals : LESS than 20 ppm • Chloride : Not more than 0.1% • Sulphate : Not more than 0.3% • Copper : Nil, complies test • Iron : Not more than 400 ppm • Soluble substance : Not more than 1.0% • Substance insoluble in acetic acid : Not more than 0.05%