6 Surface coatings of metal for electric contacts, namely, platings of silver, aluminum, aluminum alloys, iron, steel, nickel, copper, tin, zinc, or gold; coatings of metal, namely, plating compositions composed of metal, platings of silver, aluminum, aluminum alloys, iron, steel, nickel, copper, tin, zinc, or gold; veneers of metal, namely, platings of silver, aluminum, aluminum alloys, iron, steel, nickel, copper, tin, zinc, or gold