Heavy calcium carbonate, referred to as heavy calcium, is made by grinding natural carbonate minerals such as calcite, marble,  limestone. It is a commonly used powdery inorganic filler with high chemical purity, high inertness, difficult chemical reaction, good thermal stability, will  decompose below 400℃, high whiteness, low oil absorption, low refractive index, soft, dry, No crystal water, low hardness, low abrasion value, non-toxic, odorless, odorless,  good dispersion.