Zinc metal is a bluish silvery, brittle and hard material, with which one often comes across. Zinc metal is rather ignoble, but in air quickly forms an enduring protective layer. Therefore zinc metal is used a lot as corrosion prevention. Many objects made of iron, which shall be weatherproof, are zinc-plated. This is also, because zinc metal is a quite cheap material. Brass, one of the most common alloys, is made of copper and zinc. Furthermore, zinc metal is an essential trace element, which above all is needed for the metabolism and which occurs in many foods.