Coloring
Gold
Pure gold is of course yellow
in color. So how is yellow gold changed to white gold?
The answer has to do with
the metals that are added to gold to make a gold alloy.
Pure gold is 24 karat gold.
18 karat gold is 18 parts pure gold with 6 parts of an alloy
metal that can be anything other than gold--silver, for example.
When mixed with pure gold, silver produces an alloy called
"green gold"; copper results in "pink" or "red" gold, and
other metals make white gold.
White gold is usually made
by adding nickel to gold, but a superior alloy can be made
using palladium. What's the difference? Nickel is used to
make, for example, nickels. Does that sound precious? Palladium
is in the platinum group of metals. Which do you think is
more precious, more noble? Palladium white gold is by far
the better alloy. Some people are allergic to the nickel
in ordinary white gold, and tests show that nickel-based
white gold can corrode in the presence of chlorine that is
in cleaners and swimming pools, for example.
Is white gold really white?
No, there is usually a detectable trace of yellow that remains
in a white gold alloy. An oft-used method to make a new jewelry
piece look white is to plate the white gold alloy with rhodium.
The plating will wear out in time, however, and this means
that the piece will have to be replated to achieve the same
look.
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Other options for a white look in jewelry
are platinum and palladium. Platinum is a bit on the gray
side, however, and it scratches easily. Many people believe
that platinum is a hard metal, which it is not. Platinum
in its pure form is quite soft, just as pure gold is.
Platinum's great virtue in jewelry is its resistence to wear.
This explains the choice of platinum for setting very expensive
stones.
Platinum
is a bit gray, but many people appreciate
this color. Platinum in its pure form is very dense which
is why the same ring weighs almost twice as much in platinum
as it does if it were made in 14K gold. Platinum costs roughly
twice as much as gold.
Palladium is an attractive alternative
to platinum as a white metal choice. It shares many of the
same characteristics as platinum and is a fraction of the
cost. You can get 14K and 18K palladium white gold alloys
as well as a new product which is 95% pure. Contact
Ricco to discuss this option.
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