Superstitions about gemstones have existed since the earliest times and there are still a number of people who believe in their supposed powers. Many people say that gemstones possess the power to heal the body of ailments and to protect it from impending harm. Even up to now, some cultures believe that red rubies can remove evil thoughts and stress and opals can bring a myriad of internal sicknesses and diseases. Some gems are supposed to give warning of poison. It is said that in the presence of poison, an opal will turn pale and a ruby will become cloudy. Emeralds also seem to "burn" when near a harmful substance. In Europe, diamonds and sapphires were believed to dispel poison and madness, as well as witchcraft. It is said that if one placed a poisonous reptile in the same glass with a sapphire, the reptile would die from the rays of the gem.

Sometimes, beliefs about the same stones are different. For example, Europeans in the Middle Ages believed that diamonds were a symbol of the sun and could cure ailments brought about by "impure" actions. In Persia, on the other hand, people in the same period of time believed that diamonds were a source of sin and sorrow and were not worn within the vicinity of the sick.

Amethysts were considered especially effective against toothaches and headaches. Another special quality attributed to this gem by the Greeks is that wearing it would keep a drinker sober. When worn near the body, diamonds are believed to cure insanity, nightmares and leprosy. When placed on a wound, a red ruby is said to have the power to stop the flow of blood. Agate reduces fever, while carnelian stones tighten loose teeth. Some people believe that wearing jewelry with carnelians could cure tumors and strengthen their voice. Sapphires and opals are said to strengthen failing eyesight. A turquoise is said to be a primary charm against injuries brought about by falling, such as broken bones and torn ligaments. The olive-green peridot is worn as a talisman to give the wearer clarity of thought and protect him from heart diseases.

Gemstones were also worn as protection against evil and the diseases the dark spirits bring. Sapphire was originally believed to give the wearer amazing protection from the spirits of darkness and illnesses. Because of this, it is said that sapphires could help relieve ailments brought about by mental stress. Sapphires were also thought to preserve their wearer from the jealousy of his enemies. The Chinese put jade bracelets or anklets on their children to protect them from bodily harm. The Hindus used pearls as an especially strong charm to protect themselves against all kinds of evil. They also believed that wearing a red garnet makes its wearer incapable of being physically injured or wounded.

Gemstones were even thought to cure not only sickness, but depression and loneliness. Gems were thought to have the power to influence love and marriage. Turquoise used to be popular because it was thought to prevent disagreement between husband and wife, while aquamarine promote that the love of married couples. In ancient Rome, women frequently wore amethysts to be assured of their husbands love and to conquer their depression with their husbands away at war. Emeralds used to be the symbol of a happy and successful love and so were frequently used as the stone in engagement rings.