Brewsterite Subgroup

Item Description

A classic specimen of the Brewsterite Subgroup (possibly Brewsterite-(Sr)) from the Whitesmith Mine in Strontian, Scotland, featuring attractive off-white colored monoclinic crystals measuring to about 3 mm on matrix. Brewsterite is a rare zeolite species which was named in honor of Scottish physicist, Sir David Brewster, and without a doubt, some of the most well-known specimens are those from Strontian, which is the type locality for the species. If you look on mindat.org, Brewsterite-(Sr) is only reported from about 10 localities in the world, making it a very rare zeolite.
Ex Kay Robertson Collection (#2874). Kay was a prominent California collector, who specialized in European classics. She nearly lived 100 years from April 1920 - March 2020. See the article in the March-April, 2007 Mineralogical Record ( https://www.mineralogicalrecord.com/pdfs/Kay%20Robertson%20Collection.pdf ), and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017.