Welcome to the International Association for Obsidian Studies (IAOS) home page. From here, you can find out about the IAOS and explore technical information related to obsidian characterization ("sourcing") studies and obsidian hydration dating methods.

IAOS BULLETIN 69 IS OUT: All previous issues of the IAOS Bulletin are available for downloading as searchable Adobe Acrobat documents and single back issues can be downloaded using the drop-down menu below. And don't forget that a cumulative and searchable PDF of all IAOS Bulletin issues is also available in the Member's Lounge.

NOW AVAILABLE - AN UPDATED VERSION OF ARCHAEOLOGICAL AGE COMPUTATION BASED ON OBSIDIAN HYDRATION: A new verson of Archaeological Age Computation Based on Obsidian Hydration: A Summary of the Current State of the Art, by Alexander K. Rogers and Christopher M. Stevenson, is now available for downloading.

This document, first published in 2020 as a special issue of the IAOS Bulletin, has now been revised, updated, and retitled as A Summary of Obsidian Hydration Dating Science and Method for Archaeologists and incorporates advances of the last two years. Click HERE to download this latest edition.

Also available from Rogers and Stevenson is a pamphlet for Microsoft Word: How To Compute An Archaeological Age by Obsidian Hydration Dating. To download this one, click HERE.

The document is accompanied by a workbook in MS Excel for easily performing obsidian hydration dating computations. The spreadsheet can also be downloaded through the IAOS Extras page of the website.

VOLUNTEER IAOS OPPORTUNITIES: After 28 years as the IAOS Webmaster, I (Craig Skinner) am finally retiring and passing the torch in 2023. If you would like to get involved with the IAOS management team and have some very basic background in web page development and HTML coding, this could be just the volunteer or resume-building experience that you've been looking for.

But wait, there's more. I've also been looking after the IAOS World Obsidian Source Catalog (list) and this ready-for-an-update project will likewise come up vacant at the same time as the above position. If you're interested in more information about either volunteer opportunity, please get in touch with me directly at

A LOOK BACK AT THE SUCCESSFUL 2021 INTERNATIONAL OBSIDIAN CONFERENCE: Due to the threat of COVID-19 and the cancellation of University of California-Berkeley in-person gatherings, the date of the 2021 International Obsidian Conference (IOC) was changed from April 10-13 to April 30-May 2, 2021. Hosted by the International Association for Obsidian Studies (IAOS), the Archaeological Research Facility (ARF), and Far Western Anthropological Research Group (FW), this event was virtual and free for participants and attendees. An updated copy of the IOC Program can be found HERE.

Thanks to Nico Tripcevich, lightly-edited video recordings of most of the 2021 IOC talks are now available on YouTube:

The 2021 IAOS Annual Meeting was also held in conjunction with the conference. To have a look at the minutes of the meeting, click HERE.

TAKE CARE OF YOUR IAOS MEMBERSHIP DUES ONLINE: We have a membership payment option through PayPal. Click HERE for the details.

THE IAOS PDF LIBRARY: We're assembling a collection of obsidian-related theses and dissertations, all in searchable Adobe Acrobat (PDF) format. If you have a thesis or dissertation that you'd like to contribute, we would very much like to hear from you. To add a reference to the library, simply send an email to, write "IAOS LIBRARY" in the subject line of the email, and attach the PDF that you'd like to contribute. Last updated: 02/01/2023.

IAOS BULLETIN INDEX: We've added a separate index to all articles published in the IAOS Bulletin. To have a look, click HERE.

IAOS SOURCE CATALOG REVIEWERS ARE NEEDED: While we continue to maintain the IAOS World Obsidian Source Catalog, our knowledge of obsidian sources outside of the United States and Canada is sometimes incomplete or inaccurate. We would like to invite any regional obsidian source specialists to have a look at the Source Catalog and get back to us (see the email address above) if you spot any problems. We'll be happy to acknowledge your participation and we'd like to thank Dr. Maria Victoria Fernandez for her help in sorting out sources in Patagonia (Argentina and Chile), South America.

TWENTY-FIVE YEARS ON THE CUTTING EDGE OF OBSIDIAN STUDIES: Edited by Carolyn Dillian, this volume of selected readings from the IAOS Bulletin is still available for online ordering at $10 per copy (plus postage). Click HERE for a sample and all the details on how to instantly order your copy. For a review (PDF) of the book, click HERE.

IAOS EXTRAS: Be sure to have a look at the IAOS Extras page for some obsidian-related tools and resources that fall into their own unique category. These include several obsidian hydration-related tools and documents put together by Sandy Rogers and Chris Stevenson and a spreadsheet listing of obsidian-related references assembled by Chris Lloyd (updated 06-12-2019). This reference spreadsheet now contains over 5,000 literature references. The collection of references has now been ported to Zotero, an online searchable research tool, by Nicholas Tripcevich.

Contact the IAOS | Contact the IAOS Bulletin Editor

Last Updated: 02/13/2023
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