Diamond is a very attractive and costly gemstone. Diamond jewellery is a dream to many women. But only the rich can have it. Graphite is within the wood in the pencil, we write. It is very cheap and easily available.  A child in his first class gets it.

Diamond and graphite are complete opposite to each other in terms of cost, attraction and availability. But one thing connects the both. Both are created from one source. In other words, we can tell that both are born to one father. Both diamond and graphite are pure carbon. It seems unbelievable, but true.  

Carbon is a non-metallic chemical element having atomic number 6. When heated, it produces carbon dioxide. Our familiar coal, charcoal and soot are carbon. These are in amorphous form. But carbon is also found in crystalline form. Examples of crystalline forms of carbon are diamond and graphite. When heated, graphite and diamond also emit carbon dioxide. Carbon is also available in compound forms. It occurs as carbon dioxide in the atmosphere, as chalk and lime stone in carboneous rocks, as hydrocarbons in coal, petroleum and natural gas. It occurs as a major constituent of all organic substances.

Diamond is the hardest substance known. It is crystallized in such a way that there is total internal refraction in it so that it dazzles even at darkness. Diamonds were known before 3000 BC. India was the main source of diamond for a long time. The famous Kohinoor diamond, now in the British crown, was in India. Present sources of diamonds in the world are South Africa, Australia, Zaire, Botswana, Russia, Namibia and Angola. In South Africa diamonds were first discovered in 1866 and now it supplies a major portion of world’s diamond demand. The largest diamond ever found was Cullian diamond.  It weighted 3106 carats (weight of diamond is measured in carat and one carat is equal to 0.2 gram) and was found in the Premier Mine in South Africa in 1905. It was cut into 9 major and 96 small stones. The two largest diamonds, Star of Africa and Cullian II are set in the British royal regalia.

Over 80 of percent diamonds are used in industry mainly for cutting and grinding tools due to its hardness nature. Others are used in jewellery. Rough diamonds are sown and polished using a mixture of oil and diamond powder. Surat in Gujrat is a major diamond cutting centre in the world. A Swedish firm achieved the artificial synthesis of diamond in 1953. Now-a-days it is largely used in place of natural diamonds in industries.

Graphite is a blackish-grey crystalline form of carbon. It is found in many metamorphic rocks. The name graphite is derived from the Greek word graphein, which means ‘to write’. When graphite is rubbed on a surface, it leaves a dark mark. From this property the name has been derived. Graphite can be made by passing electricity through coke at 2700 degree Centigrade. Diamond is a bad conductor of heat and electricity. But graphite is a good conductor of heat and electricity.  Graphite has very high melting point (3500 degree centigrade) and so it is used for making metallurgical crucibles. It is used as lubricant and also in paint. It is used in dry batteries and for other electrical purposes. It is also used in nuclear reactor.  

Many people, mostly women must have heard the name of American diamond. It is mostly used in jewellery. It dazzles like diamond, but it is not diamond. It is not even made from carbon. It is a composite material of zirconium and silicon oxide. It is not very old. Women in America first started wearing jewels using this in 1960. Hence it became known as American diamond, although it is manufactured now-a-days in many countries. It has become popular because it looks like diamond and it is cheap so that common people can afford it.