This invention relates to zeolitic molecular sieve compositions and hybrid zeolite-silica compositions characterized by novel morphology in which the zeolite is present as macroscopic aggregates of microcrystalline zeolite. The zeolitic compositions of this invention have outstanding capability to complex multivalent cations, especially calcium due to the high exchange kinetics of the microcrystalline zeolite component and yet have the ease of handling due to the macroscopic aggregate assemblage.