Acid mine drainage where the ore is a sulfide mineral or is associated with pyrite. In these cases the predominant metal ion may not be iron but rather zinc, copper, or nickel. The most commonly mined ore of copper, chalcopyrite, is itself a copper-iron-sulfide and occurs with a range of other sulfides. Thus, copper mines are often major culprits of acid mine drainage. At some mines, acidic drainage is detected within 2–5 years after mining begins, whereas at other mines, it is not detected for several decades. In addition, acidic drainage may be generated for decades or centuries after it is first detected.
Ore Mountains animals that have been found at higher altitudes of the Ore mountains are otherwise only known from more distant places in the Sudeten mountains or the Alps. After conditions improved, once displaced species such as Eagle owls and Black storks have returned in the early 21st century. The German part of the Ore Mountains is one of the major business locations in Saxony. The region has a high density of industrial operations. Since 2000, the number of industrial workers has risen against the Germany-wide trend by about 20 percent. Typical of the Ore Mountains are mainly small, often owner-managed, businesses.