 |
 |
Making 14k Gold
Name: Jared
Status: student
Grade: 6-8
Location: KS
Country: USA
Date: N/A
Question:
How is 14 karat gold made? How are the
metals chosen, combined, melted, purified, and
cooled?
Replies:
Hi Jared,
The "karat" system of identifying the purity of gold is based on pure
gold being defined as 24 karat. Thus, 14 karat gold is 14/24ths (or
about 58.3%) pure gold by weight. The remaining 41.7% is other
metals, generally copper and silver. The ratio of the copper and gold
can vary, but usually it is "50-50"; that is, the most common
proportions of metals (by weight) used to make 14 karat gold are...
Gold: 58.3%
Copper: 20.85%
Silver: 20.85%
Sometimes the ratio of copper to silver is slightly changed to change
the color of the end product. If the percentage of copper is slightly
increased, the resulting 14 karat gold will look a little more "rosy" in
color. If the percentage of silver is increased, the result will
look a little
more white or slightly more silvery. To be called 14 karat, the
percentage of gold, however, never changes.
The reason for adding copper and silver to the gold is that pure gold is
very soft and easy to damage in jewelry. Adding copper and silver
results in a much harder alloy, and also reduces the cost. The
additional metals (copper and silver) are chosen because they result in
a harder alloy, that still looks like gold.
You asked how 14 karat gold was made. That part is easy! The three
separate metals are weighed and put into a crucible, then heated
(usually over a gas flame). Since the three separate metals are
already purified, by their individual refining processes, there is no need
to purify the result when they are melted together. Once the gold,
copper and silver are melted together, the crucible is set aside to cool.
That's all there is to it!
Regards,
Bob Wilson
Click here to return to the Material Science Archives
| |
Update: June 2012
|
|
