Wisconsin Geological Natural History Survey » .
The jamesonite is enclosed in quartz and outlines phantom. Continue Reading → Jarosite. January 18, 2013. by Linda Deith. Comments are off. Formula: KFe3(SO4)2(OH)6 Hexagonal Description: Jarosite occurs as earthy pale yellow to brown coatings, crusts and granular masses formed by the alteration of pyrite, marcasite and other iron sulfides. It is likely much more common in the state than ...