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

Residential groups that produced obsidian blades, from all time periods, also featured
production evidence in microcrystalline quartzes 67% of the time. Residential groups that
produced microcrystalline-quartz tools also produced obsidian blades 42% of the time.
Since the Balche Phase deposits only yielded evidence of one microcrystalline-quartz
tool producer and none for obsidian, there is no correlation for that time. During the
Yaxche phase, however, 100% of the obsidian-blade producing residential groups, if we
accept that PN24 was producing blades, also produced microcrystalline-quartz tools.
Exactly 50% of the residential groups associated with the production of microcrystalline-
quartz tools also had evidence of obsidian-blade production. The Chacalhaaz phase
shows more differentiation with 50% of obsidian-blade producers associated with
microcrystalline-quartz tool production. The only blade-producing group during Kumche
times was associated with the production of microcrystalline-quartz tools, but three others
featured no evidence of obsidian-blade production.
The null hypothesis, that residential groups with significant production values for
microcrystalline-quartz material will co-occur with significant production evidence for
obsidian, was not rejected. Of course, the results are more complicated than this. For the
Yaxche and Kumche phases, obsidian-tool production was always accompanied by the
production of microcrystalline-quartz tools. During the Chacalhaaz phase, however, co-
occurrence only happened 50% of the time. A single model cannot be created to explain
the entirety of this pattern. When a household group produced obsidian blades it was
likely that they also produced microcrystalline-quartz goods, but the Chacalhaaz data
shows that this is not a necessary relationship.
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