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 dock ore, in raw or taconite form. Ore docks are typically long, high structures, with a railway track or tracks along the top and a number of "pockets" into which ore is unloaded from railcars, typically by gravity. Each pocket has a chute that can be lowered to discharge the ore into the hold of a ship berthed alongside. The use of pockets and chutes allows the dock itself to be loaded with ore before it is transferred into the freighter. The docks' storage bins or pockets typically are wider at the top than the bottom, and they lead to movable