A natural magnet is an iron ore that attracts small pieces of iron, cobalt and nickel. It is usually an iron oxide with the chemical formula Fe3O4 – specifically magnetite, also known as lodestone when naturally magnetised.

Magnetite

Magnetite is a mineral composed primarily of iron oxide. Its chemical formula is Fe3O4, and it was historically described as a combination of ferrous oxide and ferric oxide.

Magnetite occurs in igneous rocks. As its name suggests, it is magnetic. Some forms of magnetite from particular locations are naturally magnetised and act as magnets themselves. Magnetite is the best-known naturally occurring magnetic mineral. Because of its magnetic properties, small iron particles can often be found adhering to its surface. When exposed to moisture, yellow-brown rust may form on the surface.

Its most important use is as a major iron ore for steel production. It is also used as a catalyst in ammonia production, as a pigment in paints and ceramics, and in the form of magnetic micro- and nanoparticles for various manufacturing processes and materials.

Researchers at Oregon State University discovered that salmon have tiny magnetite crystals in their tissues, which may help them navigate from the open ocean back to their spawning grounds.

Artificial magnets

An artificial magnet is a man-made magnet, such as an electromagnet, magnetic needle, horseshoe magnet or bar magnet.

These are also the types of magnets commonly found on refrigerator doors, and they can provide considerable magnetic force.

There are two main types of artificial magnets: temporary and permanent magnets.

Temporary magnets are not permanently magnetic, and their magnetism can be changed depending on the conditions. Examples include an electromagnet or even a steel paper clip when it becomes temporarily magnetised.

Permanent magnets retain their magnetic strength over a long period and can be manufactured to suit a specific application. They can also be designed so that the north and south poles are positioned in particular locations.

How are ferromagnetic objects attracted?

Magnets attract objects made from ferromagnetic materials. The interaction depends on the magnetic poles and the configuration of the magnetic field. Areas where the attractive effect is very weak can be described as neutral zones.

With a natural magnet, ferromagnetic materials can be attracted at different points on the surface depending on the distribution of its magnetic field.

Neodymium cylinder magnet dia. 6x4 N

Compact neodymium magnet suitable for technical and hobby applications where high magnetic strength is required in a small size.

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Neodymium cylinder magnet dia. 10x1.5 N

Low-profile neodymium magnet suitable for applications where strong magnetic force is needed while saving space.

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Neodymium prism magnet 8x4x1.6 P

Versatile rectangular neodymium magnet for mounting, holders, assemblies and other practical applications.

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Difference between natural and artificial magnets