Chemical Looping Combustion (CLC) technology is considered as one of the most promising fuel combustion methods for Carbon Capture and Storage. In CLC the oxygen is provided to the fuel by a metal oxide, therefore the direct contact between air and fuel is avoided and both CO2 and NOX emissions from fossil fuel combustion in power generation plants are greatly reduced. Simple metal oxides such as NiO, Fe2O3, or more complex such as perovskite type have been studied as Oxygen Carriers (OC) for CLC in the past. The paper shows results on naturally occurring OC which is Sinai ore, a mineral. It contains iron and manganese oxides and might be industrially applicable because to its lower production cost compared to synthetic OCs. The redox cycling reactions were carried out in a Thermo-Gravimetric Analyser (TGA). The tests were performed isothermally (750-950°C) during multiple redox cycles (5-10 cycles). For the redox reactions, methane mixtures and air were applied, with using different CH4 (<25%) and oxygen (<20% of O2) contents. Models of the redox reactions were selected using model-fitting method. For Sinai ore, 3-dimensional diffusion model was the most suitable for description of the reduction step, while shrinking core model was the best for oxidation step. The performance of the Sinai ore as an OC was compared to that of ilmenite, which is the most extensively studied naturally occurring Fe-based mineral. It was shown that the 3-dimensional diffusion model was the most suitable mechanism for describing ilmenite behaviour during redox reactions. The kinetic parameters, such as the activation energy (Ea), pre-exponential factor (A0), and reaction order (n) were determined with MathCad Prime 2.0. Both fresh and reacted samples were characterized by XRD and SEM–EDS to detect structural and/or morphological changes and determine stability of the Sinai ore over multiply CLC reactions. The results confirmed Sinai ore to be a cost effective and environmental friendly material, able to operate as OC in CLC power plants without the need for extra pre-treatment.