Majolica is a designation for an earthenware, like faience or Delft-ware, covered with a tin glazing. The addition of tin causes a white clouding of the glaze and further additions of specific metal oxides will create specific colors. The technique of Majolica was invented in the 9th century AD in the Mesopotamian region and became wide-spread in the Moslem world. After the conquest of Spain by the Moors, Majolica, here too, was produced in outstanding specimens. In the course of the Spanish conquest of Mexico, Majolica reached the New World. They were products from the region of Seville and were quickly adopted by the Aztec potters. The Mexican products strongly resembled the imported ware, except for the chemical composition. Spanish Majolica does not contain a volcanic mixture of elements in contrast to the Mexican ones.