Magnets, Magnetism, and Magnetic Gold

Pure gold is not magnetic, but alloys can be. Some charlatans sell neodymium magnets as gold testers. We spell out the facts.

Magnetism, Ferromagnetism, Paramagnetism, and Diamagnetism - Some Physics

We could make this simple, or we could make it accurate, but we will try to combine both qualities as far as possible.

Ferromagnetism

Most things we call magnetic are actually ferromagnetic.
Ferromagnetic substances include iron, nickel, cobalt and most of their alloys, some compounds of rare earth metals, cobalt, neodymium, samarium-cobalt alloys and Alnico (aluminium, nickel and cobalt) alloys.
Probably the best known of these is neodymium, but pure neodymium is not generally used, because it is too brittle, and easily corrodes, and an alloy of neodymium, iron and boron is what is used commercially.

Paramagnetism

Most other substances are paramagnetic, meaning they are attracted to magnets, but very weakly; so weakly indeed that it can usually only be detected with specialised equipment in a laboratory.
In normal everyday use, anything paramagnetic is called non-magnetic.
Paramagnetic substances include tungsten, caesium, aluminium, lithium, magnesium, and sodium.

Diamagnetism

Some substances are repelled by magnets, but weakly. These substances are diamagnetic.
Diamagnetic substances include gold, silver, copper, bismuth, mercury, lead, water, and some forms of carbon.

Ferrimagnetism and Antiferromagnetism

We do not need to discuss these, or a few other related concepts here.

Is Gold Magnetic?

No, gold (pure gold) is not what we consider as magnetic. To be more specific, it is paramagnetic, and very weakly repelled by magnets. Its magnetic fields are so weak as to be undetectable in normal everyday circumstances.

Can Gold be Magnetic?

Gold is only ever ferromagnetic if it is alloyed with ferromagnetic substances, such as iron, nickel, or neodymium. We have seen some pieces of carat (alloyed) gold jewellery which show noticeable attraction to magnets.

Can a Magnet Test for Gold?

Yes, if you don't mind getting false results! - But no, not really.
We have seen neodymium magnets offered for sale (including on ebay), as gold testers. The people selling these are charlatans, crooks, or possibly just plain ignorant.
Sometimes they will give the right answer, but then again so could a chimpanzee.
If a sample is attracted to a magnet, it is not pure gold, however this does not mean it does not contain gold. While it would be unusual for gold coins to be attracted to a magnet, it is not impossible. We have tested some gold sovereigns , and discovered a small quantity with a detectable iron content. A iron is ferromagnetic, this would show up as a false negative if someone tried to rely on a neodymium magnet as a gold testing device.

Other Gold Resources

We have a number of other pages which may be of interest to you.

• Which gold investment?
  
• Gold Sovereigns Index
  
• Pictorial Gold Coin Selector
  
• Investment Gold Glossary
  
• Gold Alloys Explained