Freehand and bipolar quartz cores classified in this analysis.

Left: types of freehand cores. F1 conical core; F2, F3, F4, F5, F6 and F7 various types of prismatic cores (with different directions of removals); F8 centripetal core; F9 multifacial core. Right: different types of bipolar cores recognised in this study, with different directions of removals. B1. Unidirectional. B2. Bidirectional. B3 is the result of rotation. B4 is typical of fracture accidents during bipolar knapping.