It can be found on top of the calcium zeolites heulandite, stilbite and epistilbite. It is associated with other zeolites such as stilbite and heulandite. It is frequently associated with other zeolites, including stilbite and heulandite. Associated minerals include quartz, apophyllite, babingtonite, heulandite, stilbite and other zeolites. It occurs with cavansite, heulandite, stilbite, analcime, apophyllite and calcite. Isomorphous with heulandite is the strontium and barium zeolite brewsterite. At one time heulandite and stilbite were considered to be identical minerals. Heulandite is the name of a series of tecto-silicate minerals of the zeolite group.