Gold is considered to be the most precious metal. It is a sign of wealth and quality. The first use of gold in the world goes back to 9000 BCE. Till now, all gold that has been mined is just enough to fill two Olympic size swimming pools . since gold does not corrode, 85% of all the mined gold , the NEAR spacecraft detected more gold on the asteroid Eros than has ever been mined on earth. About 70% of mined gold is used to make jewellery.