In the later case calcium carbonate is derived from the mixture forming a grade of product called quotprecipitated calcium carbonate or PCC PCC has a very fine and controlled particle size on the order of 2 microns in diameter particularly useful in production of paper The other primary type of industrial product is quotground In the later case calcium carbonate is derived from the mixture forming a grade of product called quotprecipitated calcium carbonate or PCC PCC has a very fine and controlled particle size on the order of 2 microns in diameter particularly useful in production of paper The other primary type of industrial product is quotground