The Organization of Chipped-Stone Economies at Piedras Negras ...

microcrystalline quartzes were reserved for small bifaces and prismatic blades, medium-
grade cherts and chalcedonies were used for mid-size bifaces (knives and spear heads),
and coarse-grained cherts and chalcedonies were used for large bifaces, especially
celtiform axes (see Chapters 3 and 4). Large indirect percussion notching flakes of fine
and medium grained materials are used to identify the production of microcrystalline-
quartz eccentrics, however few of them actually exist. Of course, there are always
exceptions, but the general trend of tougher stones for harder kinds of tasks tends to hold
at Piedras Negras.
The production of obsidian goods is identified by only a few technological types
because the morphology of imported polyhedral-cores was relatively homogeneous and
the techniques for preparing them for reduction by pressure varied little (see Chapter 6).
Nevertheless, specific stages of reduction can be identified through flake, blade, and core
morphology. The initial preparation of imported cores can be identified largely through
the existence of percussion blades and flakes that were removed to regularize the face of
the core (i.e., removing irregularities created through transport, natural inclusions, or
original production flaws). Early first- and second-series pressure-blades, and also late-
stage pressure blades that often overshot the distal end of the core mark the production of
prismatic blades. Other debitage types consist of distal, lateral, and platform rejuvenation
flakes, crested blades, and exhausted cores. Finally, the production of obsidian eccentrics
can be identified primarily by the existence of fragments of bipolarly reduced, exhausted
pressure-blade cores, irregular percussion flakes, and notching and pressure flakes
unrelated to blade-core technology. No examples of bipolar flakes used as tools were
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