Experiments with surface-softened synthetic hydroxyapatite show similar remineralization rates as surface-softened human enamel. The mineral gain with respect to time relates to parameters governing the precipitation of mineral in the specimens. A mathematical model regarding the mineral precipitation on the pore surface is fitted to the experimental values. We obtained comparable precipitation rates for apatite and tooth enamel. The geometry of the pores, however, proved to be different: a mostly tube-like pore structure must be attributed to demineralized enamel, while the synthetic hydroxyapatite specimens remineralize like a ramified, crack-like microstructure of pores.