The natural unheated yellow sapphire is a Jyotish gemstone that is used in Vedic astrology to propitiate the planet of happiness, Jupiter. Yellow sapphires are subjected to various treatments—heat, diffusion and irradiation. The heat treatment transforms them from basically worthless stones into valuable gems, hence the increase in the number of heated yellow sapphires on the market. Strong saturation in unheated yellow sapphires is very rare, making them even more valuable than the heated ones. Jupiter Gem, among its many gems, has natural unheated yellow sapphires. You can get a 6.62 carats gem, round with dimensions of 10.15 by 10.14 by 8.10 millimeters. It is a lovely yellow in color with a brilliant/step cut and no color zoning. The gem is very eye clean. It originates in Sri Lanka as well.