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Brass is any alloy of copper and zinc;
the proportions of zinc and copper can be varied to create a range of
brasses with varying properties. In comparison, bronze is principally
an alloy of copper and tin. Despite this distinction, some types of
brasses are called bronzes. Brass is a substitutional alloy. It is
used for decoration for its bright gold-like appearance; for
applications where low friction is required such as locks, gears,
bearings, doorknobs, ammunition, and valves; for plumbing and
electrical applications; and extensively in musical instruments such
as horns and bells for its acoustic properties. It is also used in
zippers, and religious items; as Menorahs.
Brass has a muted yellow color, somewhat similar to gold. It is
relatively resistant to tarnishing, and is often used as decoration
and for coins. In antiquity, polished brass was often used as a
mirror.
Brass has likely been known to humans since prehistoric times, even
before zinc itself was discovered. It was produced by melting copper
together with calamine, a zinc ore. In the German village of
Breinigerberg, an ancient Roman settlement was discovered where a
calamine ore mine existed. During the melting process, the zinc is
extracted from the calamine and mixed with the copper. Pure zinc, on
the other hand, has too low a boiling point to have been produced by
ancient metalworking techniques. The many references to "brass"
appearing throughout the King James Bible are thought to signify
another bronze alloy, or copper, rather than the strict modern
definition of brass. |