Gold has been valued by humanity since the dawn of civilization and gold jewelry never goes out of style. However, in order to make the best possible choice when buying gold jewelry it is good to know some of the basic facts as well as the "jargon" of the jewelry trade.
The first thing to know is that gold is as wearer-friendly as it is beautiful. Pure gold doesn't react with other elements to create tarnish. While some people may have an allergy or staining problem with metals combined with gold, gold itself is rarely a problem.
Gold can be worked into most shapes ranging from tiny strands to very thin sheets. One ounce of gold can even be hammered into a thin sheet spreading out over ten feet square. In short, gold can be manipulated in virtually any way the jeweler or artist wants.
How Pure Is Your Gold? Gold is used in many ways and there are varying degrees of purity in gold jewelry. Gold jewelry is marked 18K, 14K, or 10K, with the K standing for karat.
The karat system is used to describe the percentage of pure gold in jewelry. The higher the karat number, the higher the percentage of gold:
24K gold is pure gold.
18K gold contains 18 parts gold and 6 parts of one or other metals, equaling 75% gold.
14K gold contains 14 parts gold and 10 parts of one or other metals, making it 58.3% gold.
12K gold contains 12 parts gold and 12 parts of one or other metals, making it 50% gold.
10K gold contains 10 parts gold and 14 parts of one or other metals, making it 41.7% gold.
In the United States , 10K gold is the minimum karat that can be called "gold."
European Karat System
In Europe a different karat system is used to indicate the percentage of gold in a piece of jewelry. Here is the system:
18K gold is marked 750 to indicate 75% gold
14K gold is marked 585 for 58.5%
10K gold is marked 417 for 41.7%
There are other markings that are commonly found on gold. The karat marking should be accompanied by a hallmark or trademark identifying the maker and the country of origin is sometimes included as well.
Why Mix Other Metals With Gold? This is a good question. Pure gold is soft and it wouldn't be practical for daily wear. Combining other metals with it makes the gold more durable and the jewelry less expensive. However, adding other metals changes color of the gold. For example by adding nickel a jeweler is able to create "white gold." By adding copper the jeweler is able to create a "rose gold" with a pink tint, and when silver is added to gold it creates a greenish color.
Metals added to the gold result in an alloy. An alloy is the term given to a blended mixture of metals. However, the term "solid gold" can be used to describe jewelry of at least 10K in the U.S. In addition, a gold alloy of 18K or 14K can also be called "solid gold."
Gold is also used as a coating which is placed on top of less expensive metals. There are many ways to coat another metal with gold and this generally reduces the cost of the item. The thicker the layer of gold that is applied, the less likely it is to wear away, and vice versa.
Gold-Filled Jewelry is the term given to jewelry that has a gold layer. Newer gold-filled items have markings which indicate how much and what type of gold is used for the layer. The typical marking is: 1/20 12K G.F which means that the item has at least 1/20th 12K gold by weight.
Gold Plated Jewelry is another term used to indicate jewelry with a gold layer on top of other metal. The gold layer in gold-plated jewelry is thinner than the layer in gold filled jewelry, and it wears away more quickly.
Finally there is a type of jewelry designated as "gold washed." Here the layer of gold is very thin and it won't last very long.
So, what should you buy? Solid gold is durable and the better choice if you wish to wear your jewelry on a regular basis, but it is very expensive. If you have allergies to nickel or other metals then you should choose jewelry that has a high gold content, such as 18K or 22K gold.
Gold filled or gold plated jewelry is suitable for occasional wear but everyday use would diminish the gold layer exposing the metal beneath it. This could stain the skin or result in an allergic reaction. So, if you want to have a lifetime of use then choose the highest quality of gold that you can afford.