Process / pipelineChemical Kinetics

Obsidian Hydration Dating

Obsidian hydration dating (OHD) is a chronometric method that determines the age of obsidian artifacts by measuring the thickness of a hydration layer formed on their exposed surfaces. Developed by Irving Friedman and Robert Smith in 1960, it is based on the principle that fresh obsidian surfaces absorb water from the surrounding environment at a measurable rate. The method is particularly valuable in archaeology for dating volcanic glass tools and other obsidian objects, especially in regions where obsidian was commonly used for cutting and scraping implements.

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Sources

  1. Friedman, I., & Smith, R. L. (1960). A new dating method using obsidian: Part 1, the surface rind method. Journal of Geophysical Research, 65(4), 1287-1291. DOI: 10.1029/JZ065i004p01287
  2. Ericson, J. E., & Berger, R. (1975). Kinetic energy of ionizing radiation as a determinant of the obsidian hydration rate. Nature, 254(5496), 55-56. DOI: 10.1038/254055a0
  3. Mazer, J. J., Bates, J. K., Stevenson, C. M., & Clelland, J. G. (1991). Obsidian-water reactions: Measuring extremely low water contents in obsidian. Geochimica et Cosmochimica Acta, 55(2), 395-405. DOI: 10.1016/0016-7037(91)90418-6

Related methods

ScholarGateObsidian Hydration Dating (Obsidian Hydration Dating (OHD)). Retrieved 2026-06-04 from https://scholargate.app/en/archaeology/obsidian-hydration-dating