Brass is an alloy of copper and zinc. Silver readily forms alloys with copper and gold, as well as zinc. Brass is an alloy made from copper and zinc. Cobalt in compound form occurs in copper and nickel minerals. Excessive absorption of zinc suppresses copper and iron absorption. Kosovo has large reserves of lead, zinc, silver, nickel, cobalt, copper, iron and bauxite. The presence of iron, nickel, copper, and cobalt strongly activates corrosion. Alternatives to brass include other alloys containing significant amounts of copper or silver. NTCs are constructed from oxides of materials such as nickel, copper, and iron. Other pieces are created with the use of metals like gold, silver, copper and brass. Purification typically starts with the anode residues of gold, copper, or nickel production. Some of the mines in the park yielded copper, zinc, and iron. Galvanic corrosion may be severe in water systems with copper and aluminum components. The early Filipinos worked various mines of gold, silver, copper and iron. Bronze is an alloy of copper and tin.