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
Schlangenberg Nature Reserve the surface where erosion removed large amounts. About 200 million years ago aqueous metal solutions filled the cavernous rocks. Primary ores were created mostly consisting of Sphalerite, Marcasite and Galena. The process continued and the ore close to the surface decomposed due to the influence of carbon dioxide and water. In this process as a secondary ore calamine ZnCO which is known as calamine developed. Presumably the Celts had been the first digging for the calamine in the region. Ancient Celtic and Roman coins dated between 100 BC and 92/93 AD as well as remains of a Roman settlement proved