Two questions were studied in this investigation: 1) the attribution of the analyzed sherds to ancient workshops in Spain and Mexico; 2) the ancient technology. By means of mineralogical and chemical methods two ceramics groups can be differentiated. The first one is of probable Spanish origin (archaeological arguments), rich in CaO and shows temper fragments of quartz and biotite. In contrast, the second group of assumed Mexican origin has a volcanic temper and can be divided into two subgroups, one rich in CaO and one poor in CaO. The sherds of the CaO-rich Mexican group have been made by mixing of two clays, a CaO-poor, red-burning volcanic clay and a CaO-rich, white-burning marl. The CaO-poor Mexican group is composed of specimens which were made by using only one, red-burning clay, following therefore the ancient Aztec tradition. Chemically, the majolica imported from Spain and the locally made Mexican majolica are quite distinct. This can be shown by selected correlation diagrams or cluster analyses. The firing temperatures of the ancient Mexican majolica can be inferred by comparing the mineral associations of the ancient sherds with those of experimentally fired clay mixtures approaching the chemical composition of modern majolica from the workshops of Puebla. They are as high as 1050°C-1150°C for the CaO-rich group and some 850-1050°C for the CaO-poor group. Based on the known Spanish reference groups as well as the composition of modern Mexican majolica from Puebla it can be assumed that the Spanish imports came from Sevilla, and the local products from Mexico City (Puebla). -- AATA