Skulls are humanity's foremost symbol of death, and a powerful icon in the visual vocabularies of cultures all over the globe. Thirteen crystal skulls of apparently ancient origin have been found in parts of Mexico, Central America and South America, comprising one of the most fascinating subjects of 20th Century archaeology. Supposedly ancient civilizations used crystals to channel and direct energy for many purposes, spiritual and technological . Many indigenous people speak of their remarkable magical and healing properties. Today many people buy crystal skulls and use them in much the same way. People who believe in the psychic power of crystal skulls say that the skulls are a center of radiant psychic energy and have the power to increase happiness and improve people's lives just by being held, handled and spoken with; others have suggested that crystal skulls can be used like crystal balls, to aid divination.