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
Ore Mountains this is a contract between Boresch of Riesenburg and the Ossegg abbot, Gerwig, in which the division of revenue derived from ore was agreed. Grains of tin ("Zinnkörner" or "Graupen") were obtained at that time in the Seiffen mining area and gave the Bohemian mining town of Graupen (Czech "Krupka") its name. With the further settlement of the Ore Mountains in the 15th century, new, rich, ore deposits were eventually discovered around Schneeberg Annaberg and St. Joachimsthal. The "Second Berggeschrey" started and triggered a massive wave of colonization. In quick succession, new, planned, mining towns were built across the Ore