Diamonds and Coal
Coal
Coal is a dull black rock made from dead plants and trees that have been squashed under many layers of rock for millions of years.
Coal is made from the element carbon and will burn so it is used as a fuel for heating. The carbon atoms are in a random arrangement which makes the coal black.
Some coal mines are huge open areas where machinery digs up the coal. In colliery pits, miners dig under the ground and extract the coal from the rock.
Diamonds
Diamond is a solid form of the element carbon with its atoms arranged in a crystal
structure. It is formed when carbon is under high pressure and heat. Some diamonds take months to form, others could take millions of years.
Diamond has the highest hardness and thermal conductivity of any natural material so it is used in cutting and polishing tools. Diamonds are often used on the tips of drills or on polishing and grinding tools.
Cut diamonds are used in jewellery, especially in engagement rings. When polished, the different faces of the diamond reflect the light in many different directions making them sparkle.