Chalcopyrite Chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula CuFeS. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black. On exposure to air, chalcopyrite oxidises to a variety of oxides, hydroxides and sulfates. Associated copper minerals include the sulfides bornite (CuFeS), chalcocite (CuS), covellite (CuS), digenite (CuS); carbonates such as malachite and azurite, and rarely oxides such as cuprite (CuO). Chalcopyrite is rarely found in association with native copper. Natural
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