Obsidian
Volcanic glass used for blades before metal existed. Glass Buttes, Oregon offers rainbow, gold-sheen and mahogany varieties to diggers; Mexico's Pachuca green obsidian built Aztec sacrificial knives; Armenia's Gyumri flows fed the oldest known obsidian trade.
Known origins & mines
El Chayal Obsidian Source · Guatemala
Guatemala's premier obsidian quarry exploited by the Maya for 2,000+ years - tool-grade glass traded across all of Mesoamerica.…
Pachuca Green Obsidian Flows · Mexico
Aztec obsidian capital: Sierra de Pachuca green glass made sacrificial knives and trade blades exported across Mesoamerica from Teotihuacan …
Glass Buttes Obsidian Field · United States
Free public digging for rainbow, fire, mahogany and midnight obsidian flows — Glass Buttes is America's premier obsidian collecting ground.…
Gyumri Arteni Flows · Armenia
Armenian volcano flows fueled humanity's oldest known obsidian exchange networks — Neolithic blades from Artteni reached Levant sites 600 km…