The morphology changes could also be due to the decrease in suspension pH, particularly in conditions of high β. Prior works report that scalenodehral calcite particles precipitate in high alkaline pH environments, and can transform into rhombohedral forms as the suspension pH decreases. The pH of a 15 mM Ca(OH) 2 solution is ∼12.7. For C P = 75 mM, it decreased to 12.3 and 12.2 when β = 0.5 and 1, respectively. It further decreased to 11.9 when β = 2 and 11.7 when β = 4. Though these are nominal changes, it is worth noting that CaCO 3 systems are sensitive to variations in pH. Particle Specific Surface Area