Karat Gold – Understanding Gold Purity
When searching for gold jewelry we have all come across karats used to describe the quality of a piece. Most of us know that the higher the karat, the more expensive it will be. But what actually is a karat? What do the numbers all mean? What are the stamps on a gold piece?
Here is guide to understanding karats and their meaning.
What is a karat?
A karat is a measurement of the fineness of a piece of gold. The fineness of a piece represents the weight of fine metal that it contains in proportion to the total weight, including alloyed metals and any impurities. Diamonds and other gemstones are measured in carats per 200mg, meaning for every 200mg of diamond, the higher the carat.
Gold uses karats. With gold, a karat is a fractional measure of purity for gold alloys, measured per 24 parts whole. Pure gold that has not been mixed with any other metals is therefore the highest possible karat, 24 karat (24k) gold.
Whilst more valuable, pure gold is rarely used for jewelry pieces because of its softness and malleability, and tendency to scratch and mark. Therefore, it is usually alloyed with base metals for use in jewelry, altering its malleability, color and other properties.
Which karat is the best?
As mentioned above, 24 karat gold is the highest possible number in pure gold, but it is often mixed with other metals to create alloys that are more durable and more suitable for everyday wear in jewelry. The more an alloy is mixed with pure gold, and therefore the less gold there is, the lower the number of karats.
Gold is most often mixed with either silver, zinc, copper, or palladium, creating a different number of karats and different colors of gold, such as rose gold or white gold.
Traditional karats used in gold jewelry number from pure gold at 24k, 22k, 18k, 14k or 10k.
Below is a chart that explains the conversion figures of gold from percentages and decimals to karats.
Gold Conversion Chart
|Number of Karats||Fraction of Gold||% of Gold Purity||Millesimal fineness|
Does a Higher Karat Mean Higher Quality Gold?
To put it simply, no. Whilst 24k is the purest form of gold available, it does not mean it is of a higher quality. It means that there is more gold in it, and therefore it is more valuable. However, 24 karat gold is rarely used in making jewelry, as pure gold is too soft and can be easily damaged. Gold that is blended with more alloys is stronger. This is preferable especially for jewelry as the lower karats make a piece of jewelry more durable. The lower the karats in a ring, for example, the stronger it will be.
The most common karat used in jewelry and generally the most sought after is 18k gold. This means that 18 out of 24 (3/4) parts of the piece is pure gold, a relatively high number. The one quarter that is not gold will be made up of other alloys, making the jewelry more durable, better for everyday wear and slightly cheaper.
The lower the number of karats, the less amount of pure gold it contains, so the more affordable, more durable and more suited for daily use it will be.
What do the stamps mean?
Whilst it is possible come across some pieces of gold that are not stamped with purity, most gold, especially jewelry, will come stamped with what is known as a "hallmark" as a reference. Most authentic gold jewelry is stamped with some form of number or letter to indicate its karat and gold content. There are some common ones which can be helpful to understand when looking at gold that make up the vast majority of the gold stamps.
Authentic gold jewelry should have a stamp to indicate the purity of the gold in the piece. This mark can be in several different formats. For example: 585, 14kt and 14K all mean 14 karat gold. All of these formats are easy to understand, except possibly the 3 digit number format.
There are also three digit numbers tell how pure the gold is as seen in the table above. They are measured in the thousandth, so if you want to know the purity percentage, just move the decimal point in one space. For example: 750 is 75.0% pure gold (or 18 karat).
Other stamps that can be included on gold pieces can indicate whether a piece has been plated with another metal or not, e.g. GE, which stands for “Gold Electroplate”. This means that the base of a piece is made of one metal, usually brass, and a certain thickness of gold has been deposited on the base, giving it a gold plating.
How can you tell if gold is real?
There are several ways to tell if gold is real. As mentioned above, any genuine gold pieces will be stamped with a hallmark stating the content of pure gold that it contains. Always check for the hallmark. The stamp is usually found on the clasp of a necklace or bracelet, or on the inner band of a ring.
A few hallmarks, such as EPNS, EPBM, and GF, also indicate that a piece is not real gold. As with Gold Electroplate, these symbols indicate that a piece is not actually made of gold but another metal, and has simply been gold plated.
A simple test is one that can be performed at home to check if gold is real. Gold is a heavy metal, and therefore, real gold should sink. Drop your gold item into a jug of water. Any piece of supposed gold jewelry that floats is likely to be fake gold.