Construction industry is majorly criticised due to a great liberation of carbon dioxide (CO₂) into the atmosphere. Researchers have identified various techniques to capture the atmospheric CO₂. Nevertheless, the recognised methods have both merits as well as demerits. Thus, scientific communities are working on simple and easily exhibited ways of capturing atmospheric CO₂. One such technique is the conversion of gaseous CO₂ into stable calcium/magnesium carbonates. The present study was conducted to identify the carbon-capturing efficiency of olivine aggregate in cement and lime mortars. Olivine aggregate has a tendency to change its mineral structure under alkaline environment and it is able to interact with atmospheric CO₂ to form a stable carbonate. Analytical techniques (XRD, TGA) were conducted to elucidate the formation of hydrated phases formed in both lime and cement mortars. The study concluded that the addition of olivine sequestered atmospheric CO₂ and converted it into magnesium carbonate. Out of the lime and cement mortar, lime mortar captured a greater amount of CO₂ and produced stable compounds.