The small amount of nickel in US coins is unlikely potent enough to be attracted to even a magnet-fishers magnet. There is only one US cent that you will be able to find magnet fishing… the 1943 Steel Penny!
One of the main reasons some coins are magnetic is the metal they are made of. Iron and steel are magnetic, so if a coin contains these metals, it will be attracted to a magnet. This is why some older coins, such as pennies, are magnetic, while others, such as dimes and quarters, are not.
Copper-plated coins are attracted to magnets because of the iron content of the steel core, whereas bronze coins are not magnetic.
In their pure, natural forms, gold, silver, aluminum, copper, brass, and lead are not magnetic. This is because they are all weak metals. Adding iron or steel to these metals can make them stronger and magnetic. Gold is often used in coins, jewelry, electronics, dentistry, aerospace, and awards.
The science bit:
Steel is magnetic so pennies made after 1992 will be attracted to the magnet when it is close to them. Pennies made before this will not be magnetic. Since 2012, 5p and 10p coins are made out of nickel-plated steel.
The 10, 20 and 50 cent coins have no magnetic properties. The 1, 2 and 5 cent coins have a strong magnetism all over their surface.
Since January 2012, the 'Silver' 5p and 10p coins have also been made from a plated steel, in turn making them magnetic. While they changed more recently than the 'coppers', you will actually find that a higher percentage of 5p and 10p coins are magnetic.
Silver is not magnetic, not even with the strongest magnet. However, silver is diamagnetic. If you hold a silver coin at 45 degrees a suitable magnet will slide down it slowly. This is because the moving magnet sets up an 'electrical field'* that slows its fall.
A: Pure diamond is not magnetic.
Gold Alloys Are Magnetic
This includes 18k gold, 14k gold, 10k gold, and even white gold. There are different alloys of gold. The most common metals that are alloyed with gold are zinc, copper, nickel, iron, cadmium, aluminum, silver, platinum, and palladium.
To collect coins, you will need a rare-earth magnet. Rare-earth magnets are very powerful and are often used in roller coasters and maglev trains. If you have a few magnetic coins, collecting them with a rare-earth magnet takes only a second. Obtain a rare-earth magnet, such as a neodymium magnet.
While nickel is magnetic, all US nickels are actually only 25% nickel. The rest is non-magnetic copper. The small amount of nickel in US coins is unlikely potent enough to be attracted to even a magnet-fishers magnet.
The almost ubiquitous presence of small amounts of iron in ancient coins gives them remanent magnetic properties which can be measured easily on commercial magnetometers.
A magnetic wallet can ruin and damage your credit card if your credit cards are using a magnetic strip for transactions. Most older bank cards utilize magnetic strip on the back to store card info and the magnet in your wallet can erase that information.
It is possible that an 18k gold piece sticks to a magnet. 18k or 18 karat means that a specific alloy contains 75% of pure gold and 25% other metals. Since pure gold is not magnetic, gold itself will not be responsible for the magnetism, but the metal alloyed may be.
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.
Neodymium magnets are very strong and can help to test the authenticity of gold and silver bars, coins, bullion, or jewelry.
Most precious metals-like gold and copper-are nonmagnetic, and silver is no exception. Grab some magnets and see if they are drawn to your object. "Silver is not noticeably magnetic, and exhibits only weak magnetic effects unlike iron, nickel, cobalt, and the like," says Martin.
€1 and €2 coins: Their inner part is slightly magnetic. The outer part has no magnetic properties. 10, 20 and 50 cent coins: They have no magnetic properties. 1, 2 and 5 cent coins: They are highly magnetic.
Obviously, it looks different and it's called something else (what we call cents, the British call pence or simply “p”). But there are more contrasts at work. British coins are magnetic while American coins aren't.
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.