The crystal skulls are a number of human skull hardstone carvings made of clear or milky quartz rock, known in art history as "rock crystal". They are often claimed to be pre-Columbian Mesoamerican artifacts by their alleged finders, however, none of the specimens made available for scientific study have been authenticated as pre-Columbian in origin. Despite some claims presented in an assortment of popularizing literature, legends of crystal skulls with mystical powers do not figure in genuine Mesoamerican or other Native American mythologies and spiritual accounts.