Pb₂As₂S₅

This sample of dufrenoysite is displayed in the Smithsonian Museum of Natural History. Dufrenoysite is a sulfide mineral of arsenic and lead with the composition Pb₂As₂S₅ . This sample is about 7x5 cm and is from Legengach quarry, Imfeld, Binnatal, Valais, Switzerland. This sample of dufrenoysite is embedded in dolomite.