Apply a small amount of plain white toothpaste on your gold jewelry and rub it for about 30 seconds using your finger. You will see a black spot beginning to form in that place. Hold your jewelry item under running water and rinse off the toothpaste.
Test Gold Using the Float Test
Take a cup or glass, fill it up with water, now bring the gold that you want to test. Drop it into this filled glass. If the gold floats, it is surely not real but if the gold sinks to the end of the glass then it is pure gold. The real gold will sink due to being a heavy metal.
Toothpaste can damage your diamonds, gemstones, gold and silver. Toothpaste is abrasive and has a hardness of around 3/4 on the Mohs Scale of Hardness. Metals such as gold and silver are softer, so toothpaste can actually scratch damage your gold and silver jewellery.
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.
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.
Because gold is a soft metal, it is easily scratched even with a light abrasive like baking soda.
The easiest way to test gold at home is with a lighter, vinegar, a magnet, or an unglazed ceramic. All of these methods are safe and will give you a good indication of whether or not your gold is real.
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.
Aqua regia, a mixture of one part nitric acid and three parts hydrochloric acid, is used to test higher karat purity through the process of comparison and elimination.
Don't use silver polish, toothpaste, harsh chemical cleaners, or abrasive scrub brushes on gold-plated jewelry.
Test With Nitric Acid
Make a mark deep enough to scratch through the top layer of gold. Carefully apply a drop of nitric acid to the mark, and determine if the mark turns green or milky. There will be no reaction if the jewelry is either gold or mostly gold.
Does Coke Clean Gold? This is a handy and maybe unexpected tip, but Coke does indeed clean gold. You can dip your gold in a small bowl of Coke and make sure that it is completely covered. Leave the gold plated jewelry in the solution for 10 minutes and then rub with a soft cloth and rinse.
Lemon Juice Is a Great Solution
Yes, it can be used as a brass and gold cleaner.
Heat your gold jewelry with the lighter.
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.
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. Gold will not react to the nitric acid.
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).
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.
A: When you clean jewelry with vinegar, you can submerge your gold jewelry in the vinegar solution for up to 20 minutes, but it's best not to go beyond that point. It is important to note that vinegar is an acid and can react with certain metals, causing discoloration or even damage to the metal.
Place your gold piece into the water. If it's genuine gold, then it will immediately sink to the bottom of the cup. Pure gold is heavy due to its high density – 19.32 g/ ml. If your gold item floats or hovers above the cup's bottom – it's fake or plated gold.