The Acid Test All precious metals can be tested through the use of an acid test that will only harm fake materials. Genuine gold will stand up to your attempt to conduct a nitric acid test at home.
Nitric Acid Test
Gold is considered a noble metal, which means it is resistant to oxidation and corrosion from acids. This is why it shouldn't change color when it comes into contact with your skin, vinegar, or nitric acid.
Nitric acid will dissolve any non-gold base metals in your piece, while nitrohydrochloric acid will dissolve gold. To conduct the test, get a dark surface like a black stone. Rub your gold jewelry on it until it leaves a visible mark. Apply a few drops of nitric acid to the mark.
The float test works because gold is a dense metal, so it will typically sink to the bottom. On the contrary, if the piece of gold is fake, it is often made of lighter metals, so it will either float or be slower to sink.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated.
For gold, acids are designed to test to the nearest carat commonly used in jewellery, 9ct, 14ct 18ct, 22ct – but, with practice, results to within 5% can be achieved, very accurate!
Fake gold will immediately turn green where the acid is. Gold-over-sterling silver will become milky in appearance. Gold will not react to the nitric acid. The desired result is a clear drop of liquid that does not change color.
Lower-karat gold pieces may produce a mild cupric reaction, which includes minimal to no fumes, no color change, and little to no bubbling. You may see a small black mark where the acid came into contact with the piece.
Known for being very corrosive, aqua regia consists of a mixture of nitric acid and hydrochloric acid that, in the correct ratio, can dissolve nonreactive elements such as gold and platinum.
A float test using water is the easiest and safest way to tell if your gold is real at home. Start the process by taking a glass and filling it with water. Drop the gold accessory you want to test in the filled glass. If your gold piece sinks to the bottom of the glass, it is real.
The Gold Acid Test is the most popular and accurate home gold test. This is because it may harm or damage only fake materials. However, make sure to perform the acid test only if your item was identified as non-magnetic during the previous test. This helps to avoid any unnecessary expenses and actions.
14K test acid has a color coded lid and contains 12 grams of acid. Shelf life is 1 year after opening.
Real gold will not change color, but fake gold will turn either black or green. Since vinegar is an acid, it will break down any chemicals that are in the jewelry. BE AWARE that if you suspect your gold jewelry is 14k or 18k gold, putting them into vinegar might permanently discolor them.
Make a small scratch on the gold and add a drop of bleach. If it changes color, your jewelry is not 100% pure 24K gold. Bleach can permanently damage gold jewelry.
Hold a strong magnet next to a piece of gold and watch for a reaction. Gold is not magnetic, so there should not be any attraction to magnets. If there is, you most likely don't have real gold. However, some of the base metals that can be mixed with gold are also non-magnetic so you can get a false read.
If the liquid turns greenish, the item is probably mostly another metal like zinc and plated with gold. If the liquid turns a milky color, the item most likely is mostly sterling silver and plated with gold.
The apple cider vinegar gold test is a great choice if you want to test your jewelry at home, as it is readily available and easy to do. After all, real gold will not react when exposed to the acids in vinegar, toothpaste and more.
To remove the plating with a chemical solution, you only need some acetone, found in most drug stores or hardware stores. Soak your jewelry in the acetone for 15 minutes and then rinse it under warm water. The gold should come away easily!