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
Central Ore Mountains Central Ore Mountains The Central or Middle Ore Mountains ( or "Mittelerzgebirge") is a natural region that forms the central-western part of the Ore Mountains in the German federal state of Saxony. It is part of the overarching unit, the Saxon Highlands and Uplands. It forms the eastern part of the former major units, the Lower Western Ore Mountains ("Unteres Westerzgebirge", 423) and Upper Western Ore Mountains ("Oberes Westerzgebirge", 421) and is separated from the Eastern Ore Mountains in the east by the (included) valley of the Flöha, and from the Western Ore Mountains in the west by the (excluded)