The difference between solid-gold and gold-plated jewelry is related to metal composition: While solid-gold jewelry is made of a gold alloy that is consistent throughout the piece, gold-plated pieces are made of a non-gold metal that is just covered with a thin film of gold. Let’s see how you can find out whether a piece of jewelry is solid gold or gold plated.
Gold Plated Jewelry Markings
Looking at gold markings is one of the fastest ways to establish what your jewelry is made of. The most common stamp used in gold-plated jewelry is GP (standing for “gold plated”). You could also see GEP, which means “gold electroplated” and RGP (meaning “rolled gold plate”). HGE (for “heavy gold electroplate”) is another mark that indicates gold plating (you can also see HGP, which has the same meaning).
Please note that not having such markings does not mean that your jewelry is solid gold: It may simply not be stamped despite being plated.
Acid Test: The Most Reliable Method
Perhaps the most reliable way to find out the gold content of jewelry is to do an acid test. Although you can buy an acid testing kit and perform the test at home, interpreting the results can get tricky depending on the gold alloy examined. This is why we recommend that you have such a test done by a professional.
Here’s how acid testing works: The jeweler will take some sample material from your jewelry and then apply acid to it to observe if there is a color change, which will indicate what metals the sample contains. Acid testing is used mainly to determine the karat of solid gold jewelry, but it can also indicate whether the piece is plated.
Note: Solid gold does not mean pure. You should keep in mind that solid pieces consist of an alloy of gold and other metals, and the purity of this mixture depends on how much gold it contains. A piece can be made of solid gold and have very low gold purity at the same time (purity is indicated by the piece’s karat).
Another way to test what metals you jewelry contains is to use a magnet. Since gold is not magnetic, if your jewelry is attracted to the magnet, the piece must contain some other metal.
This test, however, is not conclusive for a couple of reasons. First, while a reaction of your jewelry to the magnet indicates that the piece is not made solely of gold, this does not necessarily mean that it is plated – it can still be a solid gold alloy that has low purity and contains a magnetic metal. Second, a piece may be gold plated without being attracted to a magnet if the core metal, which is covered with gold, is nonmagnetic.
The magnet test is not completely useless, however: Used in conjunction with other tests, it can give you some clues about what your jewelry is made of.
Gold Color as an Indicator
The color of your jewelry can also be used as a clue to whether the piece is solid or plated. Gold-plated jewelry is sometimes covered with 24-karat gold. In contrast, solid gold pieces are not made of pure gold as it is too soft; they are instead made of a gold alloy that contains metals that give the mixture hardness.
So, if your jewelry has an intense yellow color similar to that of pure gold and is relatively cheap (or its price is close to that of identical 10K or 14K pieces), then it may be gold plated. The best way to know that for sure, however, is to have the piece acid tested.
You can also look at the surface of the jewelry and see if its tone is even throughout or there is a change in color somewhere: If the gold plating is worn off in some places, the underlying metal will be visible there.