Jamesonite with pen for scale. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 677. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew Silver.)

Formula: Pb4FeSb6S14 Monoclinic


Jamesonite is a metallic fibrous gray mineral formed generally from hydorthermal fluids.

MARATHON COUNTY: Acicular jamesonite crystals up to 3 cm long are found in the Wausau Pluton. The jamesonite is enclosed in quartz and outlines phantom crystals (Falster, 1987).