Abstract: Applicant has discovered a new zeolite membrane and a process for preparing the same. The membrane is unique in that the zeolite crystals making up the membrane pack in a manner such that the membrane is essentially continuous with no large scale voids even when the membrane is <10 .mu.m thick. Thus, the present invention is directed toward a zeolite membrane wherein said membrane is comprised of a porous substrate and a layer of zeolite crystals wherein said layer of zeolite crystals is a polycrystalline layer with at least 99% of said zeolite crystals having at least one point between adjacent crystals that is .ltoreq.20 .ANG. and wherein at least 90% of said crystals have widths of from about 2 to about 50 microns and wherein at least 75% of said crystals have a thickness of within 20% of the average crystal thickness and wherein said membrane has at most 1 V % voids in said zeolite layer.