A method for forming calcium carbonate is provided, the method comprising the steps of: (a) milling calcium hydroxide; (b) providing a reactor vessel containing a slurry of the milled calcium hydroxide; and (c) carbonating the slurry of the milled calcium hydroxide by introducing carbon dioxide into the reactor vessel to form basic calcium carbonate by a precipitation reaction, wherein the initial reaction temperature is from about 8.degree. C. to about 15.degree. C.