Disclosed herein is are compositions comprising ground calcium carbonate having a mean particle size (d.sub.50) having a BET surface area greater than commercially available compositions having a comparable mean particle size. Viscous nonaqucous compositions and low viscosity aqueous composition comprising such ground calcium carbonate compositions are also described herein. Also disclosed are methods of grinding calcium carbonate such that the product calcium carbonate has a large mean particle size as well as a large surface area.