Spanish-Colonial majolica sherds

Figure 8. Computer projection of three-dimensional plot of cerium, lanthanum, and thorium oxide concentrations for Spanish Colonial majolica sherds. The data divides into a group having its source in Spain and a group whose source is Mexican, as discussed in the text.

In Chapter 5, Olin and Blackman explain that differences in the chemical compositions of pottery are caused by both the use of temper and by chemical and mineralogical differences in the source of the clay. Olin and Blackman report on the continuation of their studies of majolica (a common earthenware pottery) from the Spanish Colonial period in Mexico. They used INAA as well as microscopic examination of the minerals to show that majolica produced in Spain could be distinguished from that produced in Mexico. Volcanic temper was present in the ceramics produced in Mexico, and the chemical analysis of these local ceramics suggested different production centers in Mexico. The discovery of a chemically distinct group of sherds added to the typological classifications of this pottery. 

The study of tin-glazed ceramics (majolica) by neutron activation analysis was previously reported (J). The sherds studied in that research were from Spanish-Colonial sites in the New World a small number of sherds came as well from a suburb of Seville in Spain known as Triana. Although a small amount of x-ray diffraction and petrographic analysis was carried out in conjunction with that research, a number of questions remained which suggested that a much more extensive study... 

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