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

and between nodules, which were selected for different tool trajectories. Finer cherts
were used for smaller bifaces and eccentrics that required pressure flaking reduction
strategies, and medium-grade, or grainier cherts were used for medium- and large-size
tools. Coarse-grained, and tougher cherts usually were reserved for large, thick bifaces
used for heavier work. Overall, the chert can be classified as low quality because of the
large numbers of quartz crystal faults in the nodules, poor conchoidal fracture pattern,
and high degree of knapping difficulty. The ubiquity of chalcedony and chert
hammerstones at the site suggests that the local limestone was not durable enough to
provide effective hammerstones to work the local material.
Nodular and tabular cherts were collected from the limestone riverbank directly
below the site core. Chert quarrying probably was done seasonally, because the river
covers the source during the wet season. This may have also been true for architectural
construction, because much of the stone used to build the pyramids consists of river-worn
limestone cobbles. In addition, many of the facing stones, lintels, and monuments were
cut from limestone beds located on the river bar (Hruby 2001). It follows that the
acquisition of construction materials was in some way connected to quarrying of chert
materials from the same source, since one action cannot be carried out without the effect
of the other. The connection between chert and limestone is found in the geology, but
also in ancient Maya art, in which microcrystalline quartzes and limestone appear with
the same motifs, but, nonetheless, with distinct names–took’ and tuun.
The chalcedony used at Piedras Negras was locally or regionally procured, but the
actual source was not found among the local riverine stone outcrops within a two
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