Jewelers often use nitric acid to test their gold. Basically, gold won't react to nitric acid, but all other metals will turn greenish.
According to BIS, there are four components to look on the hallmarked gold jewellery to ensure the purity of gold: The standard BIS Logo/Mark. Purity in Karat and fineness. The Assaying and Hallmarking Centre's logo/number.
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.
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.
If the gold is real, the mark or streak it produces should be golden or yellow color. A black streak means you have pyrite or another form of fake gold. You can also tell if gold jewelry is fake just by wearing it. Many types of fake gold will stain or discolor your skin after about 15 minutes of contact.
(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.
Gently drop your gold item into the water. Real gold is a heavy metal and will not float, so if your gold item floats you know it is not real gold. Also, if you notice rust or tarnishing on the item after being in water, this is also a sign it is not real gold since gold doesn't rust or tarnish.
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.
One of the most foolproof methods for testing your gold jewelry is the ceramic scratch test. For this method, get an unglazed ceramic plate or piece of tiles and scrape a piece of gold across the surface. Real gold will leave a gold-colored marking, which other metals will just leave a black streak.
Goldmeter - real gold detector on the App Store.
Nearly all real gold is stamped with a hallmark that notes the karat weight of the jewelry, like 10K or 14K. This stamp is usually found on the clasp of a necklace or bracelet, or on the inner band of a ring.
The jeweller cannot sell a gold item without proper hallmarking but has the option to melt it and make a new one with the latest six-digit hallmark. Hence, as per the new rules, any jewellery item bought from now on will come with a purity certification.
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.
Because pure gold is denser than other metals, a gold item will sink quickly and directly to the bottom of a tub or bottle of water. Fake gold can float or fall more slowly. Real gold also won't rust or tarnish when exposed to water, while gold plated items can show discoloration.
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.
18 or 19 months for white(9ct) and blue(high carat) 16 or 17 months for amber(silver) 13 or 14 months for green(white metals)
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.
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.
Neodymium rare earth magnets for testing gold and silver purity.