Hi, this is an interesting question. Diamonds are very rare and special but actually they are made of the same material than for example charcoal. It is the way that the material is arranged that makes diamonds special. But let me start at the beginning.

Everything in the universe is made out of tiny tiny tiny particles. You can imagine them as being small balls. These “balls” are called ‘atoms’. Any type of material is made of those balls. Now there are two things to understand. Firstly, there are different types of ‘balls’ or ‘atoms’. For example water is made of atoms called ‘Hydrogen’ and atoms called ‘Oxygen’. The air around you is made of ‘Oxygen’, ‘Nitrogen’ and many other atoms. Now diamonds are made of just one type of atom called ‘Carbon’. This composition is the same then for example Charcoal.

Carbon atoms are also a very important part in plants, animals and humans. Therefore the material that diamonds are made of, is not very special. The second thing to understand is that the atoms can be arranged in different ways. Most often atoms attach to each other and they can be attached in different shapes and patterns. In diamond the carbon atoms are arranged very very closely to each other and the attachments between atoms are very very strong. This is why diamonds are so hard. This arrangement can only occur when the ‘Carbon is squeezed extremely strongly. In fact, you need the weight of about 120 km of rock above you to squeeze the carbon strongly enough to make diamonds. This is why diamonds are formed only deep down in the Earth.

Some smart people managed to make diamonds with machines that can squeeze strongly and those diamonds are for example used by dentists that need to drill into your teeth when you have a bad tooth.