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

differentiation in others. This is not to say that obsidian blades were the most valuable
portable goods, even chipped-stone goods, at Classic Piedras Negras, but they cannot be
easily classified as either utilitarian goods or luxury goods (see Chapter 2).
6.4: A TECHNOLOGICAL TYPOLOGY OF OBSIDIAN ECCENTRICS
Obsidian eccentrics have long been of interest for their rich symbolic content
(e.g., Blom and la Farge 1928; Gann 1918, 1930; Gann and Gann 1939; Gruning 1930,
Joyce et al. 1928; Maler 1908; Mason 1935; Meadows 2001; Price 1897-99; Rice 1909;
Stephens 1870; Thompson 1939), but less attention has been paid to how they were made
and to basic technological patterns over time and space (Clark 1996). Since Piedras
Negras features one of the largest samples of obsidian eccentrics, it is an excellent place
to examine issues of style and technology. The obsidian eccentric tradition at Piedras
Negras begins in the Early Classic period. The sample for this time period is quite small
and it is unclear if the few available examples have a direct historical connection to the
symbolism of Late Classic eccentrics. There is a technological pattern, however, in that
notched blades and flakes are typically found in the Balche and Yaxche phase deposits
and biface eccentrics tend to be restricted to the Chacalhaaz phase (see Chapter 7 for
details).
Obsidian eccentrics can be categorized into two basic technological types,
including: (1) notched cores, flakes, and blades, which can be further divided into
pressure-notched blades and flakes (Figure 6.21), and pressure and indirect-percussion
notched-cores (Figure 6.22); and (2) bifacially worked blades, flakes, and cores, which
can be further divided into partially bifaced flakes and cores (Fig. 6.23), and completely
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