Gold Jewelry

You'll find examples of pure gold jewelry, but pure gold is soft and isn't practical for daily wear. Other metals are mixed with it to make it more durable (and to lower its cost).

Adding other metals to the mix also allows metallurgists to change the color of gold. Palladium or nickel can be added to create white gold. Adding copper produces a rose or pink tint, while silver gives gold a greenish cast.

When metals are added to the gold, the result is an alloy, a blended mixture of the metals that you can think of as a very expensive cake batter. Solid gold is a term that can be used to describe an item that's at least 10K (in the US) gold all the way through. Even though it's a gold alloy--18K, 14K, or anything down to 10K--it can be called solid gold.

24K gold is pure gold.
18K gold contains 18 parts gold and 6 parts of one or more additional metals, making it 75% gold.
14K gold contains 14 parts gold and 10 parts of one or more additional metals, making it 58.3% gold.
12K gold contains 12 parts gold and 12 parts of one or more additional metals, making it 50% gold.
10K gold contains 10 parts gold and 14 parts of one or more additional metals, making it 41.7% gold.

Gold Filled Jewelry

Gold Filled wire is made by bonding, under heat and pressure, layers of karat gold to a base metal,which is then rolled or drawn to the desired thickness. Gold Filled wire is not like gold plated; there is approximately 100 times more gold in 14kt. gold filled than there is on plated wire. A Gold Filled piece is typically considered a lifetime piece of jewelry.

Gold Plated Jewelry

The gold layer in gold plated jewelry is typically thinner than the gold in gold filled jewelry, so it usually wears away more quickly. Plating is done in different ways.

You might see terms such as gold washed used to describe a very thin layer of gold--one that won't be very durable.