Ground Calcium Carbonate (GCC) and Precipitated Calcium Carbonate (PCC) are the two main types of calcium carbonate used in industrial applications. Although they share the same chemical formula, CaCO₃, their production methods, particle characteristics, and performance are significantly different.

GCC, also known as heavy calcium carbonate, is produced by mechanically grinding natural limestone or marble. The particle shape of GCC is usually irregular or blocky, and its particle size is commonly described using mesh size such as 400 mesh, 800 mesh, or 1250 mesh. Because GCC is derived from natural minerals, it offers excellent cost efficiency, stable supply, and wide availability.

PCC, or light calcium carbonate, is manufactured through a chemical precipitation process. Limestone is first calcined to produce calcium oxide, which then reacts with carbon dioxide to form very fine and uniform calcium carbonate particles. Unlike GCC, PCC is typically characterized by D50 particle size in microns, rather than mesh size, due to its ultra-fine and controlled structure.

From a performance perspective, PCC particles are smaller, more uniform, and often have a higher specific surface area. This makes PCC ideal for applications requiring high opacity, smoothness, and reinforcement, such as paper coating, specialty plastics, and high-end paints. GCC, on the other hand, is preferred in applications where cost control, bulk filling, and mechanical strength are the main concerns.

In short, GCC is mechanically ground and cost-effective, while PCC is chemically synthesized and performance-oriented. Choosing between them depends on both technical requirements and budget considerations.