Furthermore, evidence of ash-based ceramic in the area suggest that these communities were involved in a wider sphere of economic exchange at some scale, as these "volcanic petrofabrics" were likely an extra-regional import. Petrographic and contextual evidence also suggest that these petrofabrics were traded as fully formed vessels rather than the importation of raw ash to the valley region or through local sourcing of the volcanic ash. In fact, importation of raw ash is unlikely as long travel distances to ash sources would have been necessary yet no trace of existence in ethno-archaeological studies. These findings are consistent with the existence of economic relations of greater magnitude and complexity than have been traditionally assumed. This archeological study of sites in the Belize River Valley pointed to participation in economic spheres of different scales suggesting a highly complex economy: intraregional, regional and extra-regional. The data also implies the presence of regional markets or a type of redistributive system by which locally made pottery as well as regional imports circulated. The Maya had an extremely rich variety of resources that made up its currency. Cacao beans, marine shells, maize, chili peppers, manioc, amaranth, palms, vanilla, avocado, tobacco, and hundreds more resources were readily available for intensification and eventual trade throughout the Maya groups, with each resource rising and falling in value depending on its rarity. It is important to understand that agriculture began around 3000 B.C with maize and beans in a slash and burn, then individual gardens, and eventually raised terraces throughout Maya communities. Furthermore, metallurgy was not used in Mesoamerica until about A.D 600. Obsidian, jade, and other rocks and minerals were used in the production of lithic tools. Among the most important goods that circulate within the long-distance trade network were salt, obsidian, jade, turquoise, and quetzal feathers. The large market centers within major Mayan cities acted as redistribution centers in which merchants could obtain goods to sell in more minor cities. Mostly subsistence items were traded within major city market center. Meanwhile, items for the elite class such as rare feathers, spondylus and jadeite were commissioned by the elite class. The only geological sources of Mesoamerican jade was in the Maya area, specifically the Middle Motagua River Valley of eastern highland Guatemala. Because of its natural occurrence in the Maya region, jade understandably played a major role in Classic Maya economics and held religious significance.