dThe suitability of utilizing various inorganic adsorbates in the estimation of the fractal dimensions of zeolites was investigated. Consistent and sensible fractal dimension values could be obtained for the zeolites CaA, NaX, NaA, NaY and (Na, K)L by using various sets of inorganic adsorbates, especially when water, carbon dioxide, sulfur dioxide and ammonia were included in the series. (C) 2002 Elsevier Science B.V. All rights reserved.