Early vitrification stages identified in prehistoric earthenware ceramics from northern Chile via SEM

Scanning electron microscopy (SEM) has been used to investigate ceramic vitrification stages since the 1970s, however its application has been primarily restricted to stoneware and high-fired ceramics. The purpose of this study was to determine whether stages of vitrification could also be identified in prehistoric low-fired archaeological earthenware ceramics via SEM using northern Chilen samples covering a period c. 2000 to 500 years BP as a case study. This was achieved by visually comparing microstructural changes between original and re-fired ceramic sherds. The microstructural changes identified in this study indicate that the potters who made these vessels achieved early stages of vitrification. This result demonstrates that SEM is a useful technique to investigate the development of firing technology in earthenware manufacture.