Probing the mechanism of carbon mineralization in confined nanochannels provides insights into the nucleation and growth of carbonate crystals along with the preferential formation and stabilization providing implications to biomineralization, carbon sequestration and material synthesis. In the given thesis, the focus is specifically on the evolution of calcium- and magnesium-carbonate crystallization in confined volumes under the variation of solid interface from alumina to silica. Parameters like pore size, surface wettability, electrostatic charges and reaction temperature are altered to delineate the pre-nucleation behavior through MD simulations, phase transition pathway and the interfacial water behavior through experimental analysis. Results from these studies indicate that magnesium carbonate loaded in anodic alumina membrane proceeded via the transition and stabilization of hydrated phases before transitioning to stable magnesite phase with confinement significantly influencing both kinetic pathway and polymorph selectivity. Classical MD simulations revealed that hydrophilic alumina membrane stabilized the hydrated coordination shell around Mg2+ whereas hydrophobicity led to clatharate-like water structure. Extending this study with silica nanochannel solid interface investigates the formation and stabilization of nesquehonite (MgCO3. 3H2O) and hydromagnesite (Mg5(CO3)4(OH)2. 4H2O) in hydrophilic and hydrophobic environments while a pronounced reduction in water mobility in silica nanoconfinement is observed through quasi-elastic neutron scattering. Transitioning to calcium carbonate mineralization in nanoconfined alumina and silica solid interface depicts the transition from hydrated phases to metastable to stable calcite phase. In alumina interface, calcite is stabilized while silica interface promotes the stabilization of metastable vaterite and aragonite for a brief period with transition to calcite. MD simulations investigated the local density of bicarbonate, nitrate and water ions around Ca2+ giving a probabilistic idea of forming anhydrous phases over hydrated phases in nanoconfinement. To further mimic the geological conditions, reactive surface driven mineralization was explored through calcium silicate nanochannels. The reactive hosts accelerate the formation of vaterite and aragonite via silica dissolution and interfacial reaction mechanism, establishing temporal control over phase stabilization. Collectively, the thesis provides insights into the nucleation and diffusion pathways of carbonate mineralization in nanoconfinement providing a rational to develop models for geochemical transport in porous media.