FeCO3 scaling is utilised in a system of closely packed wet Fe-particles (10 μm) to prepare blocks composed of unreacted Fe-cores connected by a ‘cementing matrix of FeCO3 scales’. Within four hours of carbonation at different temperatures (30 °C – 90 °C) and CO2-pressures (1 barg–20 barg), a compressive strength of up to 160 MPa, and a siderite (FeCO3) content of up to 28 % is observed. Typical rhombohedral and atypical needle-shaped FeCO3 crystal morphologies are observed. The dependence of phase composition/morphologies on reaction conditions/processes is discussed. This study is proposed as a prelude towards utilisation of Fe-rich industrial wastes for cementation.