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

Microcores were only rarely deposited in royal caches, and instead, were discarded in
household contexts. A larger percentage of microcores are found in the near-periphery of
the site (see Webster and Kovac 2000) suggesting that the city center could have had
more access to obsidian and that microcore reduction techniques were reserved for areas
that needed to conserve obsidian.
6.2: GENERAL ELEMENTS OF CORE PREPARATION BY PERCUSSION
Since most of the percussion debitage, which usually was deposited in royal
caches, rarely exceeds 10 cm in maximum dimension, and the dorsal surfaces often
feature older (i.e., patinated) and ground percussion-scars, it is likely that many of the
cores from Piedras Negras were imported as small polyhedral-cores (Figure 6.3). It is
unknown if these cores were directly imported from the source or if they were traded
down-the-line (or rather, up the river) from the volcanic highlands of southern
Guatemala. Roughly 96% of all obsidian artifacts from Piedras Negras appear to be made
from El Chayal material originating in the highlands of Guatemala. Although there is
scant evidence, in the form of a few reduction flakes and blades, that a pittance of cores
from San Martín Jilotepeque were imported to Piedras Negras, the complete lack of
production debitage of Ixtepeque, Zaragoza, Ucareo, and Pachuca obsidian indicate that
these materials, where present, were imported as finished blades (Hruby 1999).
Furthermore, characteristics of blades made of Mexican obsidians are morphologically
distinct from the majority of blades found at Piedras Negras, suggesting the former were
produced elsewhere.
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