Where is Superfine heavy calcium carbonate

Product Name: Superfine heavy calcium carbonate
CAS RN: 471-34-1
Molecular Formula: CCaO3
Formula Weight: 100.09
Description:
Calcium carbonate is a chemical compound having the chemical formula CaCO3. It is a common substance found in rock in all regions of the world and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime and is usually the main cause of hard water. It is commonly used in medicine as a calcium supplement or an antacid, but excessive intake can be dangerous.