The precipitation kinetics of calcium oxalate was investigated using a novel acidic reaction rate control and pH-monitoring method and a sequence of acid–base, coordination, nucleation, and growth differential equations. The results indicate that the complex formation is remarkably favorable and is diffusion rate-limited. The nucleation reaction is shown to initiate via the molecular assembly of near-zwitterionically polarized complexes. From experimental results, growth and formation of the crystal phase leads to an enthalpically less stabilized state.