... less Heavy metal content 4.Appearance:white powder Our products magnesium carbonate conform in Standard:HG/T2959-2000,please check the ... %≤0.15<0.15Screening %≤0.030Used in the manufacture of magnesium, magnesium oxide, fireproof, paint, ink, pottery, glass, toothpaste, rubber, pigment, ... as fireproof and thermal insulation materials resistant to high temperature. magnesium carbonate 44.1%