In archaeology, a lithic flake is a thin, sharp fragment of stone that results from the process of lithic reduction. Once the proper tool stone has been selected, a fabricator is used to direct a sharp blow to the surface of the stone. The energy of this blow propagates through the material, producing a Hertzian cone of force which causes the rock to fracture in a specified, easily controlled fashion.
http://en.wikipedia.org/wiki/Lithic_flake

Krzemień to skała pochodzenia osadowego, która tworzy większe konkrecje (w ... było oddzielić od niego krótsze (odłupki) lub dłuższe (wióry) fragmenty, ...
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