Disclosed is calcium carbonate with a high degree of brightness, which is produced by treating calcium carbonate, and/or the milk of lime used for the production thereof by reacting milk of lime with carbon dioxide, and/or at least one of the calcium-containing intermediate products used for the production of milk of lime, with a bleaching agent before, during, and/or following said reaction. Said bleaching agent contains at least one compound of formula A[(CR1R2)SOpM(1/q)]r (I), in which A represents NR3R4, NR3, N, or OH; R1, R2, R3, R4 independently represent hydrogen or an organic radical; M represents ammonium or a metal; p represents 2 or 3; q represents the valence of M; and r represents 1 if A=OH or NR3R4, 2 if A=NR3, and 3 if A=N. Said variables are independently selected for each individual compound and/or each [(CR1R2)SOpM(1/q)] group if a mixture of compounds is used and/or if r=2 or 3.