Nine gemstones set The nine precious gems or Nav Ratans are Ruby, Diamond, Emerald, Yello Sapphire, Blue Sapphire, Gomeda, Pearl, Cat’s Eye and Coral. One should always wear a gem in a fashion that it touches the body. The cosmic rays of the planet related to the gem absorbed by the body through the gem and gives desired benefits. It is believed that all the negative energy of a planet is neutralized by the positive energy of the related gem and hence one can prevent him or her from the negative impact of the planet.