Galena 1–2% silver, a byproduct that far outweighs the main lead ore in revenue. Galena deposits often also contain significant amounts of silver as included silver sulfide mineral phases or as limited solid solution within the galena structure. These argentiferous galenas have long been the most important ore of silver. Galena deposits are found worldwide in various environments. Noted deposits include those at Freiberg in Saxony; Cornwall, the Mendips in Somerset, Derbyshire, and Cumberland in England; the Madan and Rhodope Mountains in Bulgaria; the Sullivan Mine of British Columbia; Broken Hill and Mount Isa in Australia; and the ancient mines of
Silver Valley (Idaho) the Coeur d’Alene District veins. Galena is present in veins throughout the district. Sphalerite ((Zn,Fe)S) is the second most important ore mineral, present in at least small amounts in most veins. The sphalerite is an important source of zinc throughout the ore belts. The third most abundant ore mineral is tetrahedrite (Cu,Fe)SbS. However, the tetrahedrite is responsible for the majority of the silver produced by the Silver Valley, as it’s the tetrahedrite interspersed in the galena of the district that makes it so argentiferous. There are two alpine ski areas in the Silver Valley, both easily accessible from I-90. Lookout