Following the colonisation of Mexico by Spain throughout the 15th century, it became a practice of the Spanish upper classes to eat small fragments of the búcaros, which had been broken on the journey from Mexico to Spain. Some shards were eaten whole, while others were ground down into a finer powder and mixed with water. Contemporary accounts mention the taste of Tonalá clay, but also highlight its apparent medical benefits: eating the clay was believed to aid stomach and skin problems, symptoms of menstruation and even to act as a contraceptive.