Iolite is a naturally violet-blue gemstone (known as called Neeli in Hindi). In Indian Vedic astrology, iolite is used to represent the planet Saturn (Shani), in place of the blue sapphire. Astrologically, Iolite is preffered to pricey Blue Sapphire only because it is more readily available and less expensive. For astrological purposes, bright, vivid blue iolite stones with great clarity are preferred.