Gems are often worn not as mere ornaments set in jewellery, but because of very powerful and special properties they are believed to posses. From pre-historic times, witch doctors and medicine men were convinced that certain gemstones had magical powers to cure diseases and heal wounds. They may be some psychological truth in this belief, as the very faith in the curative properties of gemstones has cured people of debilitating illness. Ancient physicians used gemstones in different ways in medical formulations to cure ailments over the ages. Perhaps the chemical nature of the gem was responsible for the cure, but the knowledge that the treatment was expensive might also have played a significant role in the treatment. Some believed in the psychological effects alone and treated illness by placing the chosen stones on the patient or by getting him to wear the stone in jewellery. Even today, patients generally resort to this form on therapy after other treatments fail
The ancient people in India believed that swallowing the powder of the highest quality diamonds would impart energy, strength, beauty, happiness, and long life. The powder of a flawed diamond was considered poisonous and caused various ailments such as cancers and diseases such as lameness, jaundice, pleurisy, and leprosy. The powder of different colored diamond was said to have different flavours, from sweet to sour or salty.
According to physicians in Europe in the fifteenth century, a diamond would heal diseases if the patient warned it with his body in his sick bed, or even breathed on it while fasting. Held in the mouth, it would stop people form telling lies. In europe till about the eighteenth century, medical properties were ascribed to gems. It is true that some gemstones do alleviate disorders; for example, pearls do cure digestive disorders because they are composed mainly of chalk, but the ancient doctors did not know this, though they found that the treatment did work. Egyptian doctors knew that hematite does coagulate the blood and stop bleeding.