Native metal brass, bronze, pewter, German silver, osmiridium, electrum, white gold, and silver-mercury and gold-mercury amalgam. Only gold, silver, copper and the platinum metals occur in nature in large amounts. Over geological time scales, very few metals can resist natural weathering processes like oxidation, which is why generally only the less reactive metals such as gold and platinum are found as native metals. The others usually occur as isolated pockets where a natural chemical process reduces a common compound or ore of the metal, leaving the pure metal behind as small flakes or inclusions. Non-metallic elements occurring in the native state include
Hajigak mining concession minor chalcopyrite. The remaining 20% is oxidized and consists of three hematitic ore types. The deposit remained unmined in 2006. The presence of coking coal nearby at Shabashak in the Dar-l-Suf District and large iron ore resources made the deposit viable for future development of an Afghan steel industry. Open pit mining and blast furnace smelting operations were envisioned by an early feasibility study. The Hajigak also includes the unusual niobium, a soft metal used in the production of superconducting steel. History reveals that Germans were the first one to exploit this deposit systematically after planning a steel mill during