... 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, dately ... as fireproof and thermal insulation materials resistant to high temperature. magnesium carbonate 44.1%