Molecular dynamics simulations have been employed to investigate the hydration and dissolution of α-quartz (0001) surfaces in a liquid water environment. Our study indicates that the structure of the water layers near the surfaces is affected by the nature of the substrate surface and by temperature. Ordered mono-layers of interfacial water molecules form in the region of the substrate where the surface is highly charged and built up of Si–O–Si bridges. As the temperature is increased this ordered mono-layer structure is gradually lost. When the surface is terminated by silanol groups, the water retains liquid-like properties even at low temperature and the molecules are distributed in a random manner, without the formation of distinct ordered mono-layers of water molecules near the surface. Taking into account the entropy of the system, the calculated energies of stepwise dissolution of a silicon species from the surface suggest that on thermodynamic grounds the complete dissolution of silicon atoms from the quartz surfaces in a liquid water environment is an endothermic process, but that the formation of a –Si(OH)₃ species at the surface would be possible. In addition, if the Si(OH)₄ species were to be dissolved, it would remain near the surface, and re-deposition at the defect-free surface is thermodynamically preferred, although there is an activation enthalpy to the first step in the process of nucleation of Si(OH)₄ at the perfect surface.