Gold Karats

As a jewelry consumer, you have probably encountered the term "karats".
24 karats denotes 100% pure gold. Any karat value below 24 is the amount of
pure gold that occupies the gold jewelry alloy. For example, 18 karat equals
18/24ths of pure gold which is 75% gold. Likewise, 14 karat equals 14/24ths
of pure gold which is 58.5% gold. The remaining mixture of non-gold metals
are not very important in determining value, but are primarily used to
increase strength and vary color in gold jewelry.

This variation in karatage value accounts for differences in prices and
colors of gold. The lower the karatage value, the wider the array of colors
and lower the price. In addition, properties such as hardness and durability
are enhanced as gold is alloyed, allowing for greater scratch resistance and
less vulnerability to damage.

The most popular karatage for jewelry in the US and Europe is 14k and 18k.
In the Middle East, India, and South East Asia, 22k jewelry is very popular.
In China and Hong Kong, "chuk kam" or pure gold jewelry of at least 990 fineness
is a traditional gift for special occasions like marriage. (990 fineness means 99% gold)
Fineness is just another way of measuring gold content per thousand parts.
So 18k, which is 75% gold becomes 750 parts of gold per thousand parts in fineness.
Below is a chart that shows the differences in popular karats.

Gold Karatage
Karats	Parts Gold	Percentage Gold	European Fineness	Preferences
24k	24/24	99.9%	999	China, Hong Kong, Taiwan, "Chuk Kam"
22k	22/24	91.6%	916	India
18k	18/24	75.0%	750	Designer Jewelry
14k	14/24	58.5%	585	Most popular worldwide
10k	10/24	41.7%	417	Minimum in USA
9k	9/24	37.5%	375	UK Standard
8k	8/24	33.3%	333	Minimum in Germany

In many countries, the law requires that every item of gold jewelry be
clearly stamped with its karatage. This is often controlled through hallmarking,
a system which originated in London at Goldsmiths' Hall in the 14th century.
US law requires hallmarking of all gold jewelry and the legal minimum gold
karatage is 10k. When buying gold jewelry, always make sure that it is properly
stamped with the karatage. Also, make sure that you know the karatage and price
when buying gold jewelry. Although the color may not differ much, the actual
value between 10k and 18k gold differs greatly.

Interesting Fact: How much space would all the gold ever mined occupy?
All the gold ever mined would form a cube measuring only 19m on each side.
This cube would, for example, easily fit under the Eiffel Tower in Paris.