One example is the presence of Pachuca obsidian from central Mexico, where Mexico City is now, and ostensibly under the control of Teotihuacan, in the Maya area during the Early Classic. While the Maya had access to a number of local obsidian sources more readily available and (relatively) easily obtained, including El Chayal its main source, Pachuca obsidian remained an important trade good. The Olmec, from the Gulf coast likewise obtained its obsidian also from El Chayal in Guatemala (Andrews (1990: 13). It is unclear if trade for foreign obsidian contributed to the growth of Maya polities, or if it simply served as a mode for obtaining superior items or human labor. Generally, obsidian came into the Maya area via larger central places, such as Tikal, Uaxactun, and Palenque. Obsidian artifacts and tools were then redistributed to smaller and potentially dependent centers and communities. This is indicated by a lack of production debitage, including polyhedral cores, decortical flakes, and large percussion flakes, among rural occupations.