King Bali was a very strong King of Rakshasa and he even defeated the Indra Dev. But he was a very generous King and people in his kingdom were very happy. The Troubled and Defeated Gods approached Lord Vishnu and asked him to save them. Maha Vishnu took the form of a small Brahmin and went to King Bali and asked him for 3 1/2 feets of land which Bali readily Donated. Lord Vishnu then assumed his Gaint ( Virath ) form and with three feet’s he measures the entire world and still 1/2 feet was remaining. Lord Vishnu completed the rest of the 1/2 feet by placing his feet on the King Bali's Chest. The area where Lord Vishnu 's feet touched on the Kings Body it turned into gems. The different parts of the body turned into different gems like diamond from head, pearl from mind etc. Totally 84 precious and semi precious gemstones came into existence from the body of King Bali. After that Indra used his Vajra and broke the body into pieces. Later Lord Shiva wore 9 of this gems on his trishul representing the 9 planets and 12 zodiacs and threw the different parts of the body in different places on the earth becoming mines.