Pearl gemstone is used in astrology to boost the power of the moon and bring serenity, wisdom, true love and happiness. It is especially beneficial for those with Cancer ascendant or if the moon is placed in the 9th, 11th or 12th house, as it can help address problems with health, family relationships or misfortune that a weak moon may cause. Pearl is the birthstone for June and should be worn on Mondays during the waxing moon phase in a silver ring on the little finger of the right hand after immersing it in holy water or milk.