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

Exhausted cylindrical cores are found at Piedras Negras, but they were likely
were too small to be held between the feet. Exhausted cylindrical-shaped cores were
found in household contexts, as well as in royal caches. The platforms were lightly
ground in most cases, but there are some examples of completely ground platforms. The
highly ground platforms appear to be a late phenomenon at the site. In some cases the
medial and distal surfaces of the exhausted cores also were ground and probably were
used as polishers, small pigment grinders, or pestles.
It is possible that the exhausted, cylindrical core resulted from the reworking of a
core of lenticular cross section (i.e., an exhausted core that resulted from the pressure
reduction of a blade core on only one or more sides, but not in the round). There is no
evidence at this point to determine whether a fully developed “in the round” reduction
strategy actually existed at Piedras Negras. Although both cylindrical and “flat”
exhausted cores were used to make eccentrics, the exhausted core of lenticular cross-
section was a more common blank. It is possible that one of the goals, among several, of
retaining a lenticular cross section was to produce blanks more amenable to the
manufacture of obsidian eccentrics.
Hintzman (2000) described another core reduction technique that focuses
primarily on one working-face of the blade core. The core is placed with the distal end
down and one face leaned against two parallel stakes or supports probably made of wood
(see Hintzman 2000:Figure 3-5). The knapper stands over the core and uses a long
wooden pressure-flaker with a hard bit to remove blades. A combination of upper body
strength and body weight is used to press the blades from the core. The downward
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