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.
Pure gold is not attracted to magnetic fields, but if an enormous magnetic field is applied to gold, the gold will slightly move and then slightly repel it. However, this is only so slightly and so no, it cannot be found with magnets.
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.
First off, if your "pure gold" is magnetic, then there is iron inside (or maybe nickel). In fact, this is one way to tell if jewelry is actually gold. If it's not attracted to a magnet then there is no iron - but it still might not be gold.
Will gold of different karats stick to a magnet? Gold jewelry, such as 18k gold, 14k gold, 10k gold, and even white gold can be magnetic depending on the alloys, or metals combined with gold, used.
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.
Look for Stamps or Hallmarks in Your Gold Jewelry
Most real gold is stamped with a hallmark that indicates its purity, aka its karat. The karat is the unit used to measure the purity of gold. The higher the karat, the purer the gold. The most common karats you'll see are 10k, 14k, 18k, 22K, and 24k.
Fool's gold is actually iron sulfide, a non-magnetic, inexpensive and abundant material that is a byproduct of petroleum production.
On the other hand, a piece may be gold plated, but it will not attach to a magnet because its core metal is non-magnetic.
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.
The Magnet Test
Since gold is not a magnetic metal, your jewelry should remain unaffected. If it sticks to the magnet, it's fake. (This test also works with silver, another non-magnetic precious metal.)
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.
Scientifically, gold is classed as diamagnetic, or magnetically inert. This means that it will not be attracted by a magnet, and cannot be turned into a magnet by applying an electrical current to it.
Will your magnetic locators find old coins, brass, gold and such? No, our magnetic locators will only locate ferromagnetic metals (i.e. iron, steel). Coins, gold and brass do not contain ferromagnetic materials.
Metals such as silver, gold, titanium, platinum, palladium, stainless steel, zinc, pewter, copper, aluminum, and tungsten are not magnetic.
eodymium magnets are very strong and can help to test the authenticity of gold and silver bars, coins, bullion, or jewelry.
The Magnet Test
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.
Apply concentrated acid to the metal. Brass will react with acids and gold will not. If you see bubbling or discoloration where the acid is applied, your piece is brass. If there is no change after applying the acid, you have gold.
Magnetic Metals
Metals you may encounter less often but are magnetic include neodymium, samarium, and gadolinium. The only time an item containing gold or silver could stick to magnets is if it was silver or gold plated.