<P> The shapes of stone tools found at Nok sites change little throughout the entire span of the Nok Culture . What tends to strike researchers is a lack of cutting tools . Apart from stone axes, no tools with a cutting edge have been found . Projectile points made of either iron or stone are also absent from Nok sites . </P> <P> Grinding tools are very common at Nok sites . They are rarely preserved in one piece, but can still illustrate the different shapes and sizes of tools used throughout the Nok Culture . Grinding stones were made of quartzite, granitic, or metamorphic rock . At the site of Ungwar Kura, grinding stones seem to have been placed in a certain order, and at the site of Ido huge grinding slabs were arranged in an upright position with pots and stone beads next to them . This context is assumed to have been ritual in some way . Most of the grinders are merely hand - sized . Throughout Nok sites, there is an abundance of grinding slabs but there seems to be a low number of hand stones . It is possible that members of the Nok Culture used these grinders until they reached a certain state of wear, and then repurposed them as pestles . </P> <P> Ground stone axes were another tool commonly used by the Nok . They were typically made from fine - grained volcanic rock (siliceous rock is also sometimes seen), and may have been used in food preparation . These ax blades tend to be smallish in size, the largest reaching 20 centimeters . Stone balls are found at almost every Nok site and are approximately palm - sized . They were probably used as hammerstones or for roughening the surface of a grinding stone . Not all of them are ball shaped, however, and many have chipping marks all over or at least in one place . These stone balls likely would have served as mobile grinding stones . </P> <P> Stone rings have also been found at Nok Culture sites . They are normally found as fragments, but can be identified as rings because of their flat, oval or triangular cross-sections and their shapes . These stone rings are very rare and their purpose is unknown . Another rare find is stone beads, which are typically found as if strung on strings . Beads tend to be carefully made out of hard siliceous rock such as quartz, chalcedony, jasper, or carnelian . There are three different bead shapes: cylindrical, which is the most common shape, as well as rod and ring - shaped . </P>

Examine the relevance of ife benin igbo-ukwu and nok to the history of nigeria