Journal of California and Great Basin Anthropology

Recent experimental work has shown that the rate of hydration is significantly influenced by the amount of intrinsic water (0H-) contained within the unweathered obsidian. A value for the intrinsic water concentration may be obtained through a nondestructive measurement of glass density, thereby permitting obsidian hydration rates to be determined for individual artifacts. As a result of these discoveries, many of the assumptions used in the normal application of obsidian hydration dating are now in need of revision. This article presents a revised set of working assumptions and procedures for implementation of the obsidian dating method and evaluates the ability of calibrations to produce chronometric dates that correspond with radiocarbon assays.