Place your jewelry on a table or hold it in your hand, pour some white vinegar on the metal directly (a dropper can also be used) if the metal of the jewelry changes its color, it is not pure gold and if it keeps shining then you have real gold in your hand.
Fill a cup or bowl with water and carefully drop your gold piece into it. If the gold is real, it will sink to the bottom of the cup. If it's fake, it will float to the top or hover in the middle of the cup.
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. Gold-over-sterling silver will become milky in appearance.
Acid test.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated. With an acid test, a small sample of the jewelry is removed and exposed to acid to induce a color change. The resulting colors indicate which type of metal the jewelry is made of.
What to do: Hold the magnet up to the gold. 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 your gold piece turns black or green when the vinegar is on it, or if it starts to smoke or fizzle at all when the vinegar touches it, it is most likely not real gold. If your gold piece does not change colors and does not fizzle or react to the vinegar in any way, it is probably real.
Goldmeter - real gold detector on the App Store.
Step 1: Bite Down On It
If it's real gold, your teeth will form small dents in the metal. Fake gold won't dent at all on a bite test! Now, before you chip a tooth, remember that gold is a soft metal so there's no need to bite down very hard.
There are over seven tests you can choose from when testing gold at home. These include the magnifying glass test, hallmark test, skin test, float test, the magnet test, and acid test. You can also learn how to tell if gold is real with makeup, and how to test gold at home with makeup.
An excellent way to distinguish brass from gold is to use the acid test. Put one to two drops of nitric acid on the product you want to test. If there is no reaction, the product is gold. If you see a green, smoky, and fizzy reaction, there is likely copper in the gold you are testing.
Check if your gold is real by performing the magnet test. Real gold will not attract a magnet. To test if 18k gold is real, hold it next to a magnet. If the magnet sticks to your jewelry, then it does not have a high percentage of gold but is made up of other, more magnetic metals.
Basically, gold won't react to nitric acid, but all other metals will turn greenish. Don't douse your jewelry in the acid—just put it in a stainless-steel dish and use a dropper to drop or Q-tip to test a tiny section. If your jewel doesn't react to the nitric acid, you have a real gold piece (14k or higher).
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. Observe the reaction, and compare the results to the chart provided in the kit.
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.
When you rub the toothpaste onto the gold, these particles work to remove a thin layer of the metal. The toothpaste will not affect real gold, but impure gold will change color. The black streak that appears is due to the presence of other metals, like copper or silver.
Place your jewelry on a table or hold it in your hand, pour some white vinegar on the metal directly (a dropper can also be used) if the metal of the jewelry changes its color, it is not pure gold and if it keeps shining then you have real gold in your hand.
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.
Fake Jewelry or Plated Jewelry Turns Your Skin Green
Over time, even the most robust metals will wear down. If your jewelry is silver or gold plated, the plating will wear down and expose the cheaper metal underneath. Your skin will react to the cheaper metal, most likely copper, and leave a green stain.