Multi-analytical study of CLAY tobacco pipes from Nditam (Centre Cameroon, west Central Africa)

This paper presents a chemical, mineralogical, textural, and physical characterization of 11 ceramic pipes (1,487-1,603 AD) from Nditam, Cameroon, with the aim of understanding their manufacture and the origin of the raw materials. Macroscopically, the pipes appear heterogeneous in terms of colour, shape, size, and decoration. From the chemical point of view, the samples were made from raw material rich in SiO2 (50-60 wt.%) and poor in CaO (0.1-2 wt.%). Mineralogical analyses show the presence of quartz, feldspar, and muscovite in all samples, whereas kaolinite, hematite, magnetite, and hornblende were detected in some of them. The presence of phyllosilicates (muscovite and, above all, kaolinite) indicates a low firing temperature of the pipes, around 700 degrees C, considering also the high open porosity measured, whereas the identification of hematite suggests a higher firing temperature but not higher than 850 degrees C, due to the lack of vitrification in the matrix of the samples. The variation in the fabric of the pipes, from very fine to small and coarse grains, suggests a pretreatment such as crushing or pounding for most of the samples. The variation in the colour of the matrix of the samples from brown to red, yellow, and black/dark indicates the use of bonfiring system. From the chemical and petrographic analyses and the geological context of the region, a local production of the samples can be deduced in comparison with a previous compositional study of ceramics from the same region. From the archaeological point of view, the stylistic heterogeneity of the samples indicates a diffusion or evolution of the pipe technology at Nditam over time. However, this stylistic variation is not reflected in the clay paste analyses. Craftsmen seem to have used the same clay pits over time, suggesting a continuity in the production of pipes.