Iron oxide copper gold ore deposits to be within Neoproterozoic to Mesoproterozoic basement. Worldwide, ages of recognised IOCG deposits range from 1.8 Ga to 15 Ma, however, the majority are within the 1.6 Ga to 850 Ma range. Ore minerals in IOCG deposits are typically copper-iron sulfide chalcopyrite and gangue pyrite, forming 10–15% of the rock mass. Supergene profiles can be developed above weathered examples of IOCG deposits, as exemplified by the Sossego deposit, Para State, Brazil, where typical oxidised copper minerals are present, e.g.; malachite, cuprite, native copper and minor amounts of digenite and chalcocite. Alteration is a mixture of sodic-calcic (albite-epidote) to potassic (K-feldspar)
Ore Mountains Mountains in the vicinity of newly discovered ore deposits. Typical examples are the towns of Marienberg, Oberwiesenthal, Gottesgab ("Boží Dar"), Sebastiansberg ("Hora Sv. Šebestiána") and Platten ("Horní Blatná"). Economically, however, only silver and tin ores were used. From that time, the wealth of Saxony was built on the silver mines of the Ore Mountains. As a metal used for coinage, silver was minted on site in the mountain towns into money. The "Joachimsthaler" coins, minted in the valley of "Joachimsthal", became famous and gave their name to the medieval coin known as the "Thaler" from which the word "dollar" is