Blue Sapphire ( Neelam) is a blue-colored precious gemstone and is considered the most powerful stone of all. Who Should Wear a Blue Sapphire? It is the birthstone for Virgo sunsign (23 Aug-23 Sep). According to Vedic Astrology, Neelam is the rashi ratna for Capricorn (Makar) and Aquarius (Kumbh). Blue Sapphire strengthens Saturn (Shani) and hence helps gain prosperity in business, wealth, sharpness of the mind and self-confidence. Ascendants of Taurus, Libra, Gemini and Virgo can also wear the Blue Sapphire gemstone.