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Gold, the only yellow metal, is rare, beautiful and
doesnt tarnish. The chemical symbol for gold is
Au, derived from the Latin word for gold aurum
meaning shining dawn. Its main uses are in jewellery,
dentistry, to adorn buildings or for other artistic
purposes but gold is also used in electronics.
In jewellery, gold is a satisfying metal to work for
it casts well and can be shaped with simple tools that
have hardly changed over many years. Golds softness
and relatively low melting point make it easy to work
into exquisite jewellery.
Of all the worlds countries, it may surprise
to know that Italy and India produce the most gold jewellery
each year.
Gold jewellery is measured in carats, the purest form
of which is 24 carat, which means about 999 parts per
thousand of the metal used is gold. Mostly this is made
into ingots because pure gold is soft and needs to be
alloyed with other metals to increase its strength.
Wedding rings generally use 22-carat gold (916 parts
per thousand, the balance is made up of other metals)
and other high quality jewellery uses 18-carat gold
(750 parts per thousand). Less expensive jewellery is
often made using 9-carat gold (375 parts per thousand).
Even when gold represents only about 50% of metal used
in a piece of jewellery, it remains highly resistant
to tarnish.
Only about 2,000 tonnes a year is mined from the earth
but a little gold goes a long way. Gold is so malleable
that one troy ounce (31.16 grams) can be hammered into
gold leaf so thin it covers 134 square metres. It is
also so ductile, that the same amount can be drawn into
a fine wire 80 kilometres long.
Gold is also used in electronic and computer circuitry,
radar equipment and satellites. When man first landed
on the moon in the Apollo 14 lunar module, his vehicle
had a film coating of gold because of its ability to
reflect intense heat. The metal is used extensively
in microchips because it is an excellent conductor of
electricity.
Learn how KCGM produces this extraordinary metal in
these pages.
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