Clay minerals are form over long periods of time, through weathering as a result of gradual chemical breakdown of rocks rich in feldspar. The extent of weathering is determined by many factors. Most common constituent mineral of clays is often one of the members of the mica mineral group. They include illite, sericite, muscovite, and biotite. Others are kaolinite, smectite, mixed-layer clays and chlorite. This paper characterizes eight clay samples from Panyam, north-central Nigeria. The characterization is based on their mineralogy and major oxide chemistry. This is aimed at determining the extent of weathering and/or maturity and origin or source of the clay materials. Compositional mineralogical and oxide analysis was performed using XRD and XRF respectively. The X –ray data revealed that the primary constituents of the rocks such as feldspars, biotite and other minerals have altered to Illite and kaolinite. Nesbitt and Young weathering trend model was used to characterizing the samples using their major oxides; four samples classified as muscovite, two as kaolinite and two as illite. From the Nesbitt and Young model, it was discovered that all samples had a granitic origin with a slower rate of weathering.
Keywords: Panyam, clay characterization, smectite, kaolinite, oxides.