THE SCIENTIFIC IDENTIFICATION OF ARCHAEOLOGICAL JET-LIKE ARTIFACTS

Jet has been widely used in the past for jewellery but was just one of a range of black lithic materials employed. When worked into small ob jects these materials can be visually indistinguishable, yet discrimin ation is important because of the restricted ocurrence of jet. X-ray f luorescence (XRF) is a rapid non-destructive discriminatory technique, but not all samples are clearly classified, and inhomogeneity may pos e problems. A reassessment of the use of XRF is reported. Other techni ques considered include electron spin resonance, infrared spectroscopy , Raman spectroscopy, thermogravimetric analysis, scanning electron mi croscopy and X-radiography. These were tested on geological materials to define an effective methodology for archaelogical material. The rec ommended approach is a combination of XRF and X-radiography, although preliminary Fourier transform infrared results showed promise. The X-r ay techniques were tested on Romano-British assemblages from Catterick and Stanwick.