... Heavy metal content 4.Appearance:white powder Our products magnesium carbonate conform in Standard:HG/T2959-2000,please ... manufacture of magnesium, magnesium oxide, fireproof, paint, ink, pottery, glass, toothpaste, rubber, pigment, dately used product industry, also as food additive and ... and thermal insulation materials resistant to high temperature. Light magnesium carbonate 44.1%(industrial grade)