During the Middle Ages topaz was thought to heal both physical and mental disorders and to prevent death.
The Greeks believed it had the power to increase strength and to make its wearer invisible in times of emergency while the Romans believed it had the power to improve eyesight. The Egyptians wore it as an amulet to protect them from injury.
Topaz was also believed to change color in the presence of poisoned food or drink. Its mystical curative powers waxed and waned with the phases of the moon. It has been said to cure insomnia, asthma and hemorrhages.