 Nearfield tichographic nanotomography was adapted for institute visualization of the hydration of commercial Portland cement in a record thick capillary. At 19 hours after mixing, a porous CSH gel shell, 500 nanometers thick, covered every alite grain, leaving a water gap between them. The spatial dissolution rate of smaller light grains during the initial acceleration phase was about four times higher than that of larger alite grains during the subsequent deceleration phase. Additionally, etch-pick development was mapped out. Laboratory and synchrotron microtomographies were used to measure the particle size distribution over time. Nearfield tichographic nanotomography will enable mechanistic studies of the dissolution precipitation process, including the role of accelerators and superplasticizers. This article was authored by Shiva Shirani, Anaquesta, Alejandro Morales Cantero, and others.