The microporous aluminosilicate minerals known as Zeolites are invaluable as adsorbents, molecular sieves and catalysts because they possess a porous structure that can let pass or accommodate cations such as, Ca2+, K+, Mg2+, Na+, etc. These are nevertheless loosely held and can be easily exchanged for those in an adjacent solution. Movement of other materials through Zeolites is naturally an important factor. The present compilation consists of diffusion data. These represent, as far as possible, pure diffusion, shorn of other transfer mechanisms such as permeation. Most of the results involve well-known artificially produced Zeolites, but also include information on naturally occurring Zeolites such as analcime and clinoptilolite. The 290 entries, 22 figures and 67 tables cover the period from 1961 to 2014.