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No precious metal is as legendary and
beautiful as gold. Gold has been used as a monetary
standard throughout the history of mankind, and ancient
gold jewelry and ornaments dating back many centuries are
still found throughout the world.
Gold is the most malleable and ductile metal, and is easy to work with. It never
tarnishes, and is unaffected by most chemicals. However,
it becomes discolored by chlorine, bleach, detergents,
and certain hairsprays and cosmetics. Gold lacks
resistance to pressure and easily bends. For this reason,
all gold jewelry is alloyed with other metals to increase
its toughness and durability.
USES
Gold
is the most useful metal in the jewelry industry. Rings,
bracelets, necklaces, earrings, and many other jewelry
figures are fashioned from gold. Ancient gold masks and
ornaments were used by many civilizations. Gold has also
been used in coinage since the earliest of days.
"Picture Rock" (white Quartz with gold veins running through it) is
sometimes polished into cabochons, creating a rare and unusual gem. Natural,
waterworn gold nuggets are sometimes made into pendants.
VARIETIES
The
color of pure gold is bright golden yellow. Besides for
strengthening the gold, other metals may be alloyed with gold to give the gold distinct color
tinges. The different types of gold are based on the
particular color tinge:
Rose Gold - Gold with
a slightly reddish hue, caused by copper
White Gold - Pale,
almost silver-colored gold, caused by nickel (and
sometimes zinc or platinum)
Green Gold - Gold with
a slightly greenish hue, caused by copper and silver
Blue Gold - Gold with
a slightly bluish hue, caused by iron
The purity of the gold depends on the percentage of
alloyed metal. This number is measured in karats.
The karat measurement determines the percentage of gold
to other metals on a scale of 1 to 24 , with 24 karats
being pure gold. That means that 14 karat gold is only
14/24 (or 58.33%) gold. Gold with a high karat
measurement is undesirable for jewelry because it is soft
and bendable, and gold with a low karat measurement is
undesirable because of its low gold content [hence lesser
value].
Gold is one of the heaviest materials. When pure, it has
a specific gravity (SG) of 19.3. The international
weight measurement of gold is the troy ounce. One troy
ounce of gold equals 31.1 grams.
FALSE
NAMES
Fool's Gold
- Miners term for Pyrite, which occurs together with gold and may
resemble it in small flakes.
SIMILAR
GEMSTONES
Many metallic alloys resemble
gold. However, they can be easily distinguished from gold
by analysis. Much gold-colored jewelry is made out of
cheap metals and coated with a very thin layer of gold.
Such jewelry is known as "gold-plated". Through
wear, the layer of gold erodes, exposing the cheaper
metal.
ALSO
SEE
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