Brewsterite is the name of a series of tectosilicate minerals of the zeolite group.

Prior to 1997, brewsterite 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 brewsterite-Sr and brewsterite-Ba.

Brewsterite-Sr, the more common of these, is a hydrous strontium and aluminium silicate, (Sr,Ba)2Al4Si12O32·10H2O.

The species are visually indistinguishable, and the series name brewsterite is still used whenever testing has not been performed.

The type locality for the series and for brewsterite-Sr is Strontian, Argyll, Scotland.