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
Galena Historic District Places. The Galena Historic District contains more than 1,000 buildings constructed before 1900 that are considered contributing properties. The center of downtown Galena is laid out in three parallel segmental tiers starting at Main Street closest to the river. Beyond Main Street, and at a higher elevation, are Bench and Prospect Streets. Main Street forms the primary commercial strip through Galena and is lined with buildings two, three, and four stories tall. Most of Main Street's structures are built of red brick and cast in Federal style of the simple commercial style of the 1840s. On Bench Street, most of