When buying gold jewelry, it is important to know what you are getting. It is one thing to pay a premium for the designer and the design, it is quite another to just get taken for a ride. Knowing even a small amount of gold terminology can make a you a much smarter shopper. The above picture is a fake bar amazon sells as a doorstop.
Carats:
Not to be confused with karats (a measure of mass), carats are a measure of purity. Divide the carats by 24 to get the percentage of gold in the material.
24 carat is pure. This is the pricey stuff, about $1000 an ounce.
18 carat is 75% pure.
14 carat is 58% pure.
8 carat is only 33% gold.
Plating:
Gold plate is a thin layer of gold electrically or chemically stuck on the outside of a piece of silver, copper, brass or other metal, often with a layer of nickel to slow the process of the other metal seeping into the gold and discoloring it. Some people are allergic to nickel, so if your plated jewelry gives you rashes, you may want to avoid nickel, though for most people, any irritation is mild and has to do with a reaction with sweat, so a ring may be more problematic than a necklace, and good earwires are important. If you see jewelry marked as 12 carat gold plate, it is just a thin film of 50% purity gold over cheaper metal, really just a chunk of copper with enough gold on the surface to make it shiny for a while.
Gold filled:
A poorly known term, gold filled is a solid layer of gold heated and pressed on to the base metal like brass, and the gold layer can be as much as 100,000 times thick as gold plate. gold filled jewelry must by law total at least 1/20th what its carat rating is by weight. Still far from solid gold, but a much better deal and unlikely to show much wear over time.
The laws are strict, so sellers are usually honest about what their product is made of, but if you don’t know at least these basics, then what they tell you will do you very little good. The next time someone tries to sell you some cheap plate with a large price tag, don’t be afraid to be snooty; walk out of there with your snoot held high.