A rare zeolitic mineral occurring in white monoclinic crystals with pearly luster. It is a hydrous silicate of aluminia, baryta, and strontia.
brewsterite
brewsterite
[′brü·stə‚rīt] (mineralogy) Sr(Al2Si6O18)·5H2O A member of the zeolite family of minerals; crystallizes in the monoclinic system and usually contains some calcium.