Stoichiometric mixtures of calcium carbonate and silicon oxide have been mechanically activated by milling during several hours (29 and 50) previous to the solid state reaction, in order to obtain dicalcium silicate, Ca 2SiO4. X-ray powder diffraction and differential thermal analysis studies show that the mechanical processing of the powders induces changes in the orientational uniformity of crystallites and the diminution of the decomposition temperature of the calcium carbonate. Microlamellar particles of β-Ca2SiO4 were obtained when the solid state reaction was achieved at 1450°C, whereas β-Ca2SiO 4 and α'L -Ca2SiO4 phases were obtained when the reaction took place at 1000°C. By means of the powder processing described in this work, we can prepare phase β-Ca 2SiO4 without any chemical stabilizer and with an unusual lamellar morphology.