Is gold magnetic?

At it's simplest, gold is not magnetic. As if often the case however, the answer is somewhat more complicated than it may first appear.

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. In fact, if placed in a magnetic field, gold will very weakly repel the magnet (though this may only be observed under sensitive laboratory conditions).

The above is true on the macro scale, but on a nano-scale, new research shows that tiny clusters of gold atoms do have paramagnetic properties. This means they act like miniature bar magnets and can attract other magnetic objects. The density of gold atoms stop this from occurring naturally, however. Recent studies have also shown that heat can further increase gold's hidden magnetic properties.

Does gold stick to a magnet?

Pure gold, does not stick to a magnet in most real-word cases, and should be slightly repelled if pure. As discussed below however, a lot of gold items are not necessarily pure, so they could stick to a magnet depending on the other metals used within it.

Magnetism occurs in materials which have an odd number of electrons. In these materials the odd, unpaired, electrons are attracted to the unpaired electrons in other materials. When the electrons in each object are aligned, or magnetised, this pulls the two objects together.

Unlike many other materials, gold’s unpaired electrons cannot be aligned and instead bond with each other - because of its extreme density. This negates the ability for strong paramagnetic fields to form in gold.

It also explains a number of gold's unique properties; a high melting point, very low reactivity, and high electrical conductivity.

Gold Plated vs Real Gold

If a magnet attracts an apparently gold object, it is either impure, gold-plated or fake gold. Apart from attempting to deceive, there are legitimate reasons a gold product would be impure or gold-plated.

Gold is soft and malleable. Often it is deliberately mixed with other metals to form a harder gold alloy. Jewellery, if made from pure (24 carat or 99.9% fineness) gold, can be easily damaged. For this reason, most jewellery is 18 carat – eighteen in twenty-four parts gold – or 9 carat – nine in twenty-four parts gold.

Depending on the other metal mixed with gold, this could result in the alloy having magnetic properties. Silver, for example, is similar to gold and is also diamagnetic, this means White Gold (if silver was used) should also be non-magnetic. Conversely, iron is sometimes found in gold, or is used for clasps on jewellery, and is highly magnetic.

Gold plating is the act of covering a base metal object in a thin veneer of the precious metal. This can be done as a cost-saving method, but it is also used extensively in electronics, and as a means of protecting other materials from erosion or tarnishing.

Is magnetism a good test for gold?

As mentioned above, the metals that are used to compose a gold alloy will determine how magnetic it might be. For this reason, testing with a magnet – even a strong magnet – should only be used as a rough guide to the purity of gold. One thing that can be guaranteed is that if a magnet picks it up then it is not pure gold. This does make magnetic testing somewhat useful for certain coins and bars. If a gold coin is claimed to be 99.99% pure then it should not be attracted to a magnet.

More reliable tests are recommended though. This includes looking for hallmarks, performing acid tests or, better still, consulting a reputable gold dealer or jeweller. There is more information about testing gold in our article on how to tell if gold is real.