A novel approach, designated as the particle-mediated, nano-scale, aggregation route, to the formation and growth of spherical and colloid-sized anhydrous carbonate mineral particles and hierarchically organized biomineral carbonate structures is discussed. This model is inconsistent with the conventional crystallization mechanism, which is primarily based on diffusion growth. It is determined by the initial formation of nanosized, crystalline particles, (singlets), and their subsequent aggregation into submicrometre and micron-sized carbonate particle assemblies. This concept is much more common in Nature than has previously been assumed. The number of new examples of its significance in the formation of inorganic and biogenic carbonate mineral solids has significantly increased in recent years. A few illustrations are presented to show the appearance of nanostructured and hierarchically organized carbonate particles formed through the nano-scale aggregation route in natural systems, together with those obtained from laboratory model experiments.