Stilbite is the name of a series of tectosilicate minerals group. Prior to 1997, stilbite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named: * stilbite-Ca * stilbite-Na
Stilbite-Ca, by far the more common of the two, is a hydrous calcium sodium and aluminium silicate, Na 27Al ). In the case of stilbite-Na, sodium dominates over calcium. The species are visually indistinguishable, and the series name stilbite is still used whenever testing has not been performed.