Sankofa Magazine: Ghana's Illustrated Arts and Culture
The article examines objects recovered from the stone age site at Wenchi in Brong Ahafo made of some type of fine clay which had some element of iron content. It seems some of the objects were baked after having been dried in the sun. The faces were then carefully scored with criss-cross or grid pattern, or single line decorations. A number of uses has been posited, including message sticks, ritual objects, and pottery-making tools, among others.
Agorsah, E.K. (1981, Jan-June). Mystery Objects of the Ghanaian Stone Age, Sankofa Magazine: Ghana's Illustrated Arts and Culture, Vol. 5(1), 44-45.