This artifact was critical in contributing data demonstrating the limitations of optical measurement and the superiority of SIMS for analyzing hydrated obsidian.
Obsidian artifacts occur at many archaeological sites throughout the world.
In 1960, Friedman and Smith developed a way of dating obsidian artifacts by optically measuring the thickness of the hydrated rind that develops on fresh obsidian surfaces over time. Unfortunately, the initial promise of the method has never been realized because obsidian hydration dates are often both imprecise and inaccurate. It also avoids the measurement limitations inherent in optical microscopy. Moreover, this new method opens the possibility of obtaining paleoclimatic data from the hydration rind through analysis of hydrogen and oxygen isotope ratios. A detailed report of the initial findings of this project is in press with the Journal of Archaeological Science .