A range of scientific techniques have been applied to this material (SEM, XRD, AAS, infrared spectroscopy, and petrology) in order to characterize the fabrics used and to estimate the temperature attained during the production of the copper. Sherds of locally-produced pottery were also analyzed to compare their fabrics with the refractory ceramics and to estimate their firing temperatures. At Timna, high refractory noncalcareous clays containing substantial proportions of kaolinite were used to make furnace walls and tuyeres. The Layer 2 crucibles from Timna and elsewhere, however, were of calcareous clays, possibly because the lime in the clays reacted with the slag formed in the crucible and lowered its melting temperature and viscosity. -- AATA