Found in igneous rocks which are formed from cooled lava or magma is the mineral we call diamond. Diamonds are formed from carbon are crystal shaped and are so hard they are used for tools that cut, grind, shape and Polish. Only a diamond can cut or grind another diamond.
A diamond is also one of the most valuable gemstones. A perfect diamond is colourless and the biggest one ever found is called the Cullinau which is set in the royal crown of Britain. It was found in a South African diamond mine and weighed more than 1ΒΌ pounds before it was cut. Another large and famous diamond is the Indian Kohinoor. Once it was a peacock's eye in the throne of an Indian mogul. Now it can be seen among the crown jewels in the Tower of London where it is set in the coronation crown of Queen Elizabeth the Queen Mother.
WHAT ARE BLACK DIAMOND
Diamonds are mineral composed of carbon. Coal is a mineral with carbon in its composition. It is also black in colour and so came to be known as BLACK DIAMONDS.
More than 300 million years ago in the Carboniferous period of the Earth, plants appeared then over the years partially decayed. As they lost moisture they gained more and more carbon until they hardened into layers of rock. This was coal.
When it was discovered as far back as Roman times, the coal burned were mined and use as fuel. From the 19th century when the Industrial Revolution was in full swing, coal was not only used as fuel but burned to give coke and coal gas for heating and lighting. It was also burned to produced coal tar which led to the study of Chemistry, the dyes industry, the explosives industry and the plastic industry. Natural gas has now almost taken the place of coal gas for heating and illumination as coal gas contains carbon monoxide which is poisonous.
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