Let’s make this clear – in its pure form, gold is NOT magnetic.
Magnetism is a key property of nature that causes objects to attract or repel each other stemming from electron motion within atoms. Magnetic force manifests within a field characterized by direction and strength which acts upon materials or magnets within it.
Why Gold Is Not Magnetic
Materials can be classified as either non-magnetic, diamagnetic, paramagnetic or ferromagnetic depending on the alignment of atomic moments. Non-magnetic materials exhibit no magnetic properties while diamagnetic materials are repelled by when in a magnetic field.
Alternatively, paramagnetic materials display weak attraction when in the presence of a magnetic field. However, ferromagnetic materials display the strongest attraction to magnetic fields making them the best materials in making magnets.
While gold has some unique properties, it is not inherently magnetic especially in its pure form when it is considered non-magnetic.
This is because gold lacks the atomic properties and electron arrangement to exhibit paramagnetism or ferromagnetism. As such, gold is incapable of aligning magnetic moments to generate a considerable magnetic field.
A diamagnetic material generates a magnetic field in the applied external magnetic field’s opposite direction. The result is a repulsive effect when these magnetic fields interact.
Gold in its natural form exhibits diamagnetism, which is a weak form of magnetism. The diametric response for gold is very weak typically unnoticeable and practically negligible for most practical purposes.
While gold in its pure form is not magnetic, magnetism can be induced by alloying with certain materials. The alloying elements typically have magnetic properties that they pass on to the resulting gold alloy.
The alloying ratio required to make gold magnetic depends on the magnetic material being used. Furthermore, the alloying ratio will vary with the desired magnetic properties and the intended application.
Note that these gold alloys typically display weaker magnetism than the pure form of alloying elements. Some of these alloys include:
i. Gold-Iron Alloys: Iron is a ferromagnetic material allowing its combination with gold to result in a magnetic alloy. A magnetic gold-iron alloy typically requires a significant amount of iron usually one part gold to one part iron.
ii. Gold-Cobalt Alloys: Gold and cobalt can be combined in different ratios to achieve the desired magnetic properties in the alloy. You can find gold-cobalt alloys consisting 90% gold to 10% cobalt or 80% gold to 20% cobalt.
iii. Gold-Nickel Alloys: These alloys find use in specialized applications where gold’s properties and nickel’s magnetism are needed. Alloying gold with nickel requires the addition of substantial nickel material usually in a 50:50 ratio.
iv. Gold-Samarium Alloys: A Samarium is a rare-earth element known for its strong magnet properties. Samarium can be combined with gold in different ratios depending on the application to produce niche magnetic gold alloys.
Gold’s magnetic properties are not the element’s defining characteristic. Gold is instead utilized for its luster, corrosion resistance and malleability. However, where magnetism is desired alongside gold’s other properties, alloying gold with a magnetic material comes in handy.