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.
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.
Pure gold is virtually indestructible. It will not corrode, rust or tarnish, and fire cannot destroy it. This is why all of the gold extracted from the earth is still melted, re-melted and used over and over again.
Gold is a heavy metal, so heavy that it will sink in water. If you drop your jewelry in a glass of water, real gold will drop straight down. Remember that 18- karat gold is 75% gold mixed with other alloys.
Gold is called a heavy metal because of its high density, which comes from the fact that each of its atoms is individually very heavy.
Drop the Item in 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.
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.
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.
The dore has to go through a trial by fire at a refinery. In an exciting process called refining, it is re-liquified in a furnace and then heaped with generous amounts of soda ash and borax. This effectively separates the gold from impurities and other metal traces.
(If you're combing through the remains of a burned building, you should be able to recognize metals visually, right?) Here's a quick guide: Gold will still look like gold – shiny and bright – even after exposure to high heat, and even if it has melted, because gold does not oxidize.
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.
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.
One study showed that when a 14K white gold ring was placed in common household bleach for 36 hours, the ring completely disintegrated! Small amounts of chlorine exist in tap water, too.
The Acid Test
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.
Step 4: Feel By Weight
Fake gold feels lighter than real gold and that is because gold is heavier than almost all other metals. This is not the most reliable test, but if the gold item feels practically weightless then that is one indication that the item is fake.
Since gold is both paramagnetic and diamagnetic, both cancel one another out and become weak. So a strong magnet will attract gold ever so slightly and will also repel it.
Fool's gold is actually iron sulfide, a non-magnetic, inexpensive and abundant material that is a byproduct of petroleum production.
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.
It indicates that the material's composition is 92.5% silver and 7.5% copper. This means it's both fairly malleable and bright. However, some people assume that when a piece of gold jewelry features this hallmark, it means the piece has a gold content of 92.5%. This is not the case.
Gold does tarnish and scratch over time. To preserve the luster of your gold jewelry, avoid exposure to household bleach and other cleaning products, which will quickly cause gold to discolor and possibly disintegrate.
It's generally not recommended to wear any type of gold-plated jewelry, including 18k gold-plated jewelry, in the shower or while swimming.