Nickel silver, Mailechort, German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum is a copper alloy with nickel and often zinc. The usual formulation is 60 opper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong (cupronickel). All modern, commercially important nickel silvers (such as those standardized under ASTM B122) contain significant amounts of zinc, and are sometimes considered a subset of brass.