Diamond is the purest form of naturally occuring carbon. It is found as colourless, lustreless solids which can be transformed into brilliant gems. It consists of an array of bonded atoms. No discrete molecules can be distinguished.
Diamond crystal is octahedral in shape. It is a giant molecule in which the carbon atoms are closely packed and held by strong covalent bonds.
Artificial diamonds are made by subjecting graphite to very high pressure and temperature for several hours in the presence of a catalyst such as rhodium or nickel.
Properties of Diamond
- It is the hardest known substance.
- It has a high melting point.
- It is very dense and resistant to high temperature and chemical attack.
- It is a non-conductor of heat and electricity, because it has no free valence electrons.
Uses of Diamond
- Being very dense and hard, diamond is used as abrasives to sharpen very hard tools.
- It is used in the manufacture of glass cutters and rock breakers.
- Diamond is also used as pivot support in precision instrument.
- Its high refractive index makes it valuable as jewellery.