Two parallel cuts are made into the edge of the artifact using a lapidary saw equipped with 4-inch diameter diamond-impregnated .004″ thick blades. These cuts produce a cross-section of the artifact approximately one millimeter thick which is removed from the artifact and mounted on a petrographic microscope slide with Lakeside thermoplastic cement. A New Dating Method Using Obsidian: Part I, The Development of the Method. The mounted specimen slide is ground in a slurry of 600 grade optical-quality corundum abrasive on a plate glass lap. This initial grinding of the specimen reduces its thickness by approximately one half and removes any nicks from the edge of the specimen produced during cutting. Hydration rinds smaller than one micron often cannot be resolved by optical microscopy. The Failure of Obsidian Hydration Dating: Sources, Implications, and New Directions.
Is Obsidian Hydration Dating Affected by Relative Humidity?
The effects of these variables have often been summarized and will not be discussed further here (Michels and Tsong 1980; Friedman and Obradovich 1981; Freter 1993; Hull 2001; Stevenson et al., 1993, 1998, 2000; Friedman et al. 1999, Ridings 1996; see Skinner and Tremaine 1993 for additional references).
Once a hydration layer has been measured, it can be used to determine the relative ages of items or, in some circumstances, can be converted into an estimated absolute age.
Justin Dugan is co-curator of the Archaeolgoical Dating musuem. Dugan is currently a junior at Wichita State University and his major is Accounting.
He works on his farthers farm and is also the president of a fraternity at Wichita State.
elcome to the Northwest Research Obsidian Studies Laboratory website.