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About Gold.
You can rely on GemOptions Jewelry for
fine quality solid karat gold.
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Pure gold
(fine gold) is softer than pure silver but harder than
tin. Its beauty and luster are unmatched by any alloyed
gold. The extreme malleability, ductility, and softness
of pure gold make it practically useless for jewelry
applications.
The addition of alloying elements (other metals) to gold
are used to increase the toughness and hardness of the
metal. While almost any metal can be alloyed (melted)
with gold, only certain metals will not dramatically
change the color or make the metal brittle. The addition
of indium, for instance, turns gold purple and gives gold
the workability of glass.
Over time, certain percentages of gold have become
legally recognized "karats." Karat indicates the amount of gold as a
percentage of the total, i.e. 24 karat is 100 percent gold. Thus 14
karat is 14/24's gold or 58-1/3 percent gold. Gold standards vary around
the world. In the United States, 18, 14, and 10 karat gold are the only
ratings allowed to be sold as karat gold.
In karat gold, there is a balance of metals in the
non-gold percentage. These metals provide the various
colors and hardness of karat gold. Typical alloying
elements and their color effect are:
Copper Reddening
Silver Greening
Zinc Bleaching
Nickel Whitening
Palladium Whitening
Examples of the compositions of different colors are:
Yellow Gold, copper, silver, zinc
White Gold, copper, nickel, zinc
Red Gold, copper
Green Gold, silver
Adjusting the proportions of coloring agents provides the
array of colors on the market. Additional metals enhance
properties such as cast-ability, grain size, hardness,
corrosion resistance, color, workability, ultimate
strength, and others. These additions can dramatically
change the properties of the karat metal for better or
worse.
Knowing how the additions will affect the metal greatly
enhances the possibility of a superior final product. In
deep drawing of metals, it is important to have a metal
which will elongate or stretch a great deal before
fracturing, thus high ductility. The requirement for an
earring post would be a high tensile strength (a great
deal of force needed to get the material to permanently
deform, bend). It is imperative to select the proper
karat composition for the desired application.
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We do not
recommend
white gold filled, yellow gold filled,
nickel plate, and
yellow plated jewelry.
The term gold filled
refers to the manufacturing process in which an ingot of
base metal, usually copper, is bonded with thinner ingots
of gold. A "sandwich" is formed by mechanically bonding a
layer of gold on both sides of the copper ingot. This
"sandwich" is then cold worked by rolling or drawing
until a much thinner gauge metal is achieved. Products
are then formed or die-struck from this layered material.
The object is then gold plated to hide the edges, as they
would otherwise reveal the sandwiched construction.
Although gold-filled product is readily available today,
this process was most popular in the early 1900's.
Hallmarking will appear as 1/20th 14k gold filled,
indicating that by weight, 1/20th of the metal content of
the product is 14k gold.
Rolled gold plate refers to the same process; however the
gold content is lower; for example, 1/30th 12k. In your
question, the reference to white and yellow is simply an
indication of the color of the gold used. The advantages
of this product are that the gold layering is much
thicker, and longer wearing, than gold plating. It is
also much less expensive than a similar product made of
all 14k material.
When a product is referred to as gold, rhodium, or
nickel-plated, this indicates that it has been
electroplated with a thin layer of that particular metal.
The terms gold electroplate, or gold plated, indicates an
electrolytically applied coating of gold over a base
metal. The plated coating must not be less than 10k in
fineness, to a minimum overall equivalent of seven
millionths of an inch of fine gold. A coating that is any
thinner must be marked gold flashed or gold washed; if
the coating is equivalent to 100 millionths of an inch of
fine gold it may be marked Heavy Gold Electroplate or HEP.
Since only a micro thin layer of the metal is deposited
on the base object, electroplating is inexpensive and in most cases
tends to wear off easily.
You can rely on GemOptions
Jewelry for fine quality solid karat gold.
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