Archaeological obsidian studies in the American Southwest and beyond have significantly matured in the last two decades. Like ceramic analysis, obsidian artifact analysis has become a key factor in many archaeological projects because obsidian used to produce chipped stone tools is common across time periods in the Southwest—from Paleoindian through colonial periods. Even today, making stone tools from obsidian is used in teaching. 

In the last twenty years, not only have the ways archaeologists use obsidian provenance to address twenty-first-century issues changed, but we now also see geologists and paleontologists using obsidian in ways never before imagined.

In the second edition of Obsidian, author M. Steven Shackley examines the newly discovered sources of archaeological obsidian and other volcanic rocks on both sides of the U.S.-Mexico border. This work has aided in building new inferences concerning exchange, group interaction, and social networks: subjects that were only emerging twenty years ago in obsidian studies. 

The field of obsidian provenance studies is truly international, linking archaeologists and geologists in the United States like never before. While the obsidian sources covered in this volume are regionally specific, the applications and methods used in the understanding of source recording, composition issues, and provenance are relevant worldwide.

M. Steven Shackley is an emeritus professor of anthropology and geoarchaeology at the University of California, Berkeley, and director of the Geoarchaeological XRF Laboratory in Albuquerque.