Assertion: hard hammer | /r/HasProperty | their oblong shape
Facets:
Source sentences:
text: Among the oldest are those cited by Jean and Nicole Chavaillon in both Gomboré 1B, Melka Kunturé and even Olduvai (layers I and II): Active hard hammers are distinguished by their oblong shape with one or two active edges with numerous shock marks and often small flakes (chipping), as well as some cracks.