Nanometre to micrometre scale interfacial processes control CO2 mineralisation in silicate rocks targeted for carbon sequestration. Understanding the chemical mechanisms prompted by the addition of CO2 into aqueous-rock systems is necessary to design and manage industrial scale mineralisation operations. This work presents a synthesis of the past two decades of research on chemical processes taking place at the solid mineral interface, and how they drive or inhibit ex-situ or in-situ mineralisation. Studies cited in this review focus on samples representative of mafic or ultramafic rocks, their constituent mineral phases, and the calcium silicate wollastonite. Key findings include 1) Mechanical passivation is not caused solely by silica formation, a variety of chemical species can inhibit reactions by forming pervasive layers, including the target carbonate phase. 2) The functionality of engineered carrier solutions primarily derives from sodium bicarbonate which provide a pH buffering effect, excess CO32– ions, and limit mass transport resistance from Si-rich passivating compounds. 3) Non-uniform mineralisation is exhibited in whole rocks and can be attributed to the inherent pore characteristics and heterogeneous distribution of grain sizes that produce micro-environments of preferential carbonation in natural mafic rock samples. 4) Thin water films facilitate a coupled dissolution-re-precipitation mechanism in water-bearing supercritical (CO2-rich) environments. 5) Mineralisation in both aqueous and supercritical CO2 systems generates product layers of comparable morphology, consisting of interstratified carbonate-silica growths. Yet, experiments involving a wet supercritical CO2 phase tend to generate carbonates at lower temperature conditions indicating enhanced reactivity or a more porous passivating layer.