Chalcedonite grains (0.8-1.25 mm) were modified with MnO2 and used for sorption of Mn2+ ions from their aq. solns. (pH 6) under static, paradynamic and dynamic conditions. The sorption equil. was modeled by the non-linear regression method using the Lan gmuir, Freundlich and Redlich-Peterson isotherm equations. The exptl. data from static batch expts. were described in the best way by the Lan gmuir equation, which confirmed a monolayer sorption of Mn(II) onto the sorbent surface. The exptl. data from paradynamic batch and dynamic flow expts. were described in the best way by the Redlich-Peterson and the Freundlich equations because of multilayer phys. sorption under the conditions. Max. sorption capacity was the smallest under static conditions (1.25 mg/g). In paradynamic and dynamic expts. the capacity was twice or triple higher (2.21 or 4.10 mg/g, resp.).