Apply the flame to the jewelry for about a minute or 60 seconds. Watch it closely for any changes in color. Fake gold will get darker, while pure gold will do the opposite: it will get brighter the hotter it gets. The brighter your jewelry gets, you can rest assured you have real gold.
Will gold turn black when you burn it with a lighter? The gold will not turn black when you burn it with a lighter. However, if your piece of gold jewelry turns black when you burn it with a lighter, it is most likely fake.
How to Test If Gold Is Real with a Lighter. The first test is also the easiest test: try to burn your gold. If it's real gold, it will get brighter as you apply the flame but it won't actually catch fire and burn. If your gold piece starts to smoke or gets darker, you likely have imitation gold.
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.
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.
Place a magnet against the potential gold item.
If you feel as if the magnet is being drawn or pulled downward, then the item is not pure. The other metals in the item, such as nickel, are responding to the magnet. A pure gold piece will not draw the magnet, since non-ferrous.
Scratch test.
If you cut deep enough that you expose underlying metal, you can assume that it is plated. If it appears to be made of a uniform composition throughout, then it is probably solid gold.
Genuine gold will stand up to your attempt to conduct a nitric acid test at home. Make a tiny mark on the piece of gold to penetrate the surface. Drop a small amount of liquid nitric acid on that scratch and wait for a chemical reaction. Fake gold will immediately turn green where the acid is.
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. It can't tell you if your gold is fake, since most gold jewelry has other metals mixed in to give it strength.
While brass is not bright yellow, it's more dull than gold. However, gold is much shinier causing its golden color. Impurities can cause the shiny metallic luster that is characteristic of gold to fade. The purity of the gold determines the shine of ornaments.
Counterfeit solid gold usually darkens, changes color, or shows burned marks when heated. The color change may not disappear even after fake gold cools down. If your solid gold shows any of these changes, it likely contains significant amounts of bronze, brass, copper, iron, nickel, or zinc.
Some types of gold, such as gold-plated items and gold that has been alloyed with other metals, may be attracted to magnets. This is because these types of gold have a higher concentration of electrons, which makes them more susceptible to magnetic attraction.
Pure gold on its own cannot stick to a magnet. However, if you have an alloy of gold, then it could stick to a magnet. An example of a gold alloy that may stick to a magnet is gold with over 20% of its atoms replaced by iron. In very cold temperatures this alloy of gold may magnetize all on its own.
Goldmeter - real gold detector on the App Store.
If it's real gold it will not stick to the magnet. (Fun fact: Real gold is not magnetic.) Fake gold, on the other hand, will stick to the magnet. If that necklace leaps to the magnet, your significant other has some explaining to do.
The Sound Test
If you give copper a gentle thump or gingerly knock it against something, listen closely: It will have a muted, softer sound. Red or white gold, for example, will ring out with more of a clanging, bell-like sound.
Pinchbeck is a form of brass, an alloy of copper and zinc mixed in proportions so that it closely resembles gold in appearance.
Brass and gold are the two that are most commonly used interchangeably — I'm guilty — due to their similar yellow undertone, where you'll see bronze is warmer...more red, almost brown, making it a lot easier to distinguish.
You will also need a small file or sandpaper to scratch the surface of the gold to be tested. To perform the test, first, scratch a small area of the gold with the file or sandpaper. This will remove the top layer of gold, exposing the inner layer. Next, apply a small drop of nitric acid to the scratched area.