The areas surrounding the Pek's course are rich in a variety of ores and minerals, like copper, iron, pyrite, zinc, wolfram and coal ("Rakova Bara" coalmine), but the river is famous for the gold which it brings from the mountains around Majdanpek in small amounts, so from time to time, a media coverage of the gold findings (more often used as a publicity stunts) provoke gold rush in the region. For this, the river is nicknamed "Zlatni Pek" (Cyrillic: "Златни Пек"; "Golden Pek").