Saturn (Shani). A blue Sapphire is one of the most powerful gems of all. It counteracts all enviousness from others and keeps away from evil. It alleviates long-term misfortune. Sometimes this stone reacts adversely so it should always be tested for a few days before finally wearing. A blue Sapphire could give you everything you desire - health, wealth, longevity and happiness. It also restores lost wealth and prosperity.