Obsidian use in Mesoamerica
Obsidian is a naturally formed volcanic glass that was an important part of the material culture of Pre-Columbian Mesoamerica. Obsidian was a highly integrated part of daily and ritual life, and its widespread and varied use may be a significant contributor to Mesoamerica's lack of metallurgy.
Source: Wikipedia — Obsidian use in Mesoamerica (CC BY-SA 4.0)