Mineralogically, bentonites are dominated by smectites and due to characteristic textural and physicochemical properties of smectites (e.g. very small particle sizes, high cation exchange capacity) are of a great use in industrial applications. In this study, a bentonite sample was characterized with regard to the particle size distribution, mineralogical composition and cation exchange capacity in comparison with the data for the two internationally well-known bentonites representative for Na- and Ca-bentonites: the Mx-80 bentonite of Wyoming, USA and that of Milos, Greece, respectively. Results show a high fraction of fine-grained particles, which demonstrates high yield of purified clay. Mineralogically, the studied bentonite comprises mainly smectites and expandable illite-smectite mixed layer clay minerals. Main accessory minerals are calcite, silica polymorphs and zeolites. The specific surface area and cation exchange capacity values are 330.3 (m²g^-1) and 42.2 (meq/100 g), respectively. It is concluded that the mineralogical, textural and the measured physicochemical properties of the studied bentonite is applicable to the applications in oil industry and its related environment maintenance related issues.