Brewsterite is a rare mineral consisting of a complex silicate of the zeolite family, occasionally found in volcanic rocks. Also referred to as zeolite, brewsterite takes its name after the Scottish natural philosopher and inventor Sir David Brewster. The mineral has been characterized by its unique crystal structure, which makes it a valuable specimen for mineral collectors. Common synonyms for brewsterite include white zeolite, magnesium zeolite, calcium zeolite, and clinoptilolite. Other mineral varieties, such as stilbite and heulandite, are also often used interchangeably with brewsterite, as they share similar physical and chemical properties.