biface

A hand axe is a prehistoric stone tool with two faces that is the longest-used tool in human history. It is usually composed of flint or chert. It is characteristic of the lower Acheulean and middle Palaeolithic (Mousterian) periods. Its technical name (biface) comes from the fact that the archetypical model is a generally bifacial Lithic flake with an almond-shaped (amygdaloidal) morphology. Hand axes tend to be symmetrical along their longitudinal axis and formed by pressure or percussion. The most common hand axes have a pointed end and rounded base, which gives them their characteristic shape, and both faces have been knapped to remove the natural cortex, at least partially. Hand axes are a type of the somewhat wider biface group of two-faced tools or weapons.