This volume is the third in the Advances in Archaeological and Museum Science series sponsored by the Society for Archaeological Sciences (SAS). The purpose of this series is to provide summaries of advances in various topics in ar chaeometry, archaeological science, environmental archaeology, preservation technology, and museum conservation. The SAS exists to encourage interdisciplinary collaboration between archaeologists and colleagues in the natural and physical sciences. SAS mem bers are drawn from many disciplinary fields. However, they all share a common belief that physical science techniques and methods constitute an essential component of contemporary archaeological field and laboratory studies. The series editors wish to thank the reviewers of each of the chapters in this volume for their excellent comments and suggestions. We also wish to thank Chriss jones for her invaluable assistance in the preparation of the texts for submission to the publisher. xi Preface As noted in the introductory chapter, this volume is the second major review of research progress in the study of archaeological obsidian. An earlier book, Advances in Obsidian Glass Studies: Archaeological and Geochemical Perspectives, appeared in 1976. A comparison of the treatment of topics reflected in this earlier work and that contained in this volume not only highlights important advances in the quality and depth of research on archaeological obsidian over more than a quarter of a century but also illustrates more generally some characteristics of developments in the archaeological science field in general.