THE BEGINNINGS OF ISLAMIC STONEPASTE TECHNOLOGY*

A multidisciplinary programme of research on Islamic pottery has been focused on questions of the dating, provenance and technology of Islamic pottery. One particular question has been the development of stonepaste, a material made primarily of crushed quartz with added frit-glass and clay. The combination of the different approaches of this study has revealed early foundations for the technology in ninth-century AD Iraq, apparently originating in the clay ceramic rather than the ‘Egyptian faience’ tradition. Subsequent and final practice developed in tenth- and eleventh-century AD Egypt. This technology becomes the primary body for all fine Islamic ceramics.     

A PILOT STUDY IN NON-CONTACT LASER PHOTOTHERMAL ARCHAEOMETRY OF ANCIENT STATUARY PEDESTAL STONES FROM CYPRUS

Several samples of geological stones from statuary pedestals found in various archaeological sites in Cyprus have been characterized using non-contact laser infrared photothermal radiometry. Thermal diffusivities and effective optical absorption coefficients were calculated using a one-dimensional thermal-wave model. The mean values and standard deviations were tabulated and comparisons were made with lithographic and petrographic studies of the samples. Good correlations were found, thus demonstrating that laser photothermal archaeometry is a promising methodology for the accurate, potentially non-destructive and convenient characterization of the origins of ancient stones in Cyprus and other geological and archaeological sites.     

AN ASSESSMENT OF BACK-SCATTERED ELECTRON PETROGRAPHY AS A METHOD FOR DISTINGUISHING MEDITERRANEAN OBSIDIANS

The recent application by Burton and Krinsley (1987) of back-scattered electron (BSE) petrography to obsidians from sources located in the south-western United States established that this method can effectively resolve and characterize included micro-crystalline phases that have proven difficult to analyse by optical thin-section microscopy. In the first extension of their original study, we have examined, using BSE petrography, obsidians from island sources located in the Mediterranean, including sources known to have been exploited in prehistory. Because of the kinetic contrasts on their crystallization, these microcrystalline phases reflect the magmatic history of the obsidian, providing information about superheating, supercooling, sub-solidus processes, and other phenomena. This information is of significance for the chemical analysis of Mediterranean obsidians and also as the basis for a powerful alternative to existing non-destructive analytical methods for the sourcing of archaeological and art-historical obsidian.     

WHITE LUMPS IN FIFTH- TO SEVENTEENTH-CENTURY AD MORTARS FROM NORTHERN ITALY

Ancient mortars from northern Italy, dating from the fifth to the seventeenth century AD, were examined in order to formulate an hypothesis regarding the origin of the white lumps often observed in these mortars and in other samples of the same geographical provenance. Various characterization techniques were employed, including scanning electron microscopy, X-ray powder diffraction and Fourier transform infrared (FTIR) and micro-FTIR spectroscopy.     

LIME PLASTER AS AN ADHESIVE FOR HAFTING EIGHTEENTH-DYNASTY FLINT SICKLES FROM TELL EL DAB'A,EASTERN NILE DELTA (EGYPT)*

A combination of analytical techniques, including thin-section observations, scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis, was applied to study the nature and origin of an adhesive used for mounting flint sickle blades to a wooden handle, recovered from early Eighteenth Dynasty culture layers of the multi-layer settlement at Tell el Dab'a, Lower Eygpt. The results obtained from these investigations led to the conclusion that the adhesive is a pure lime plaster, thus providing the oldest evidence for the use of this material as a binding agent so far known in ancient Egypt.     

THE PROVENANCE AND TECHNOLOGY OF NEAR EASTERN GLASS: OXYGEN ISOTOPES BY LASER FLUORINATION AS A COMPLEMENT TO STRONTIUM*

The ability to make rapid measurements on small samples using laser fluorination enhances the potential of oxygen isotopes in the investigation of early inorganic materials and technologies. δ¹⁸O and ⁸⁷Sr/⁸⁶Sr values are presented for glass from two primary production sites, four secondary production sites and a consumer site in the Near East, dating from Late Antiquity to the medieval period. δ¹⁸O is in general slightly less effective than ⁸⁷Sr/⁸⁶Sr in discriminating between sources, as the spread of measured values from a single source is somewhat broader relative to the available range. However, while ⁸⁷Sr/⁸⁶Sr is derived predominantly from either the lime‐bearing fraction of the glass‐making sand or the plant ash used as a source of alkali, δ¹⁸O derives mainly from the silica. Thus the two measurements can provide complementary information. A comparison of δ¹⁸O for late Roman – Islamic glasses made on the coast of Syria–Palestine with those of previously analysed glasses from Roman Europe suggests that the European glasses are relatively enriched in ¹⁸O. This appears to contradict the view that most Roman glass was made using Levantine sand and possible interpretations are discussed.     

LEAD ISOTOPE ANALYSIS OF ARCHAEOLOGICAL METALS BY MULTIPLE‐COLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY*

Lead isotope ratios in archaeological silver and copper were determined by MC–ICPMS using laser ablation and bulk dissolution without lead purification. Laser ablation results on high‐lead metals and bulk solution analyses on all samples agree within error of TIMS data, suggesting that problems from isobaric interferences and/or mass bias variations due to the presence of matrix elements are insignificant. Inaccurate laser ablation analyses on low‐lead copper reflect erroneous mass bias corrections from use of a non‐matrix matched standard. However, in most cases, silver and copper are analysable for lead isotopes by bulk dissolution or laser ablation MC–ICPMS with simplified sample preparation.     

DAMAGE ASSESSMENT AND PRESERVATION OF AN EGYPTIAN SILVER VASE (300–200 BC)*

An Egyptian metal vase from the Ptolemaic period was investigated metallurgically and fractographically. The metal is nearly pure silver. Despite its high purity (in archaeological terms) it is severely embrittled and cracked, mainly along grain boundaries. Factors contributing to this damage are work-hardening and residual microstructural deformation (slip and twinning), corrosion along slip lines and twin boundaries, corrosion in bauds that are the remains of coring, large equiaxed grains, externally applied forces and internal residual stresses. The metal is now friable. This must be taken into account during any further restoration of the vase: a procedure is suggested.     

Technology Transfer at the Periphery of the Mycenaean World: The Cases of Mycenaean Pottery Found in Central Macedonia (Greece) and the Plain of Sybaris (Italy)*

The study of technology transfer in pottery production to the periphery of the Mycenaean world has been addressed by considering two different areas, southern Italy and central Macedonia. Technological features such as ceramic paste, decoration and firing have been determined for different ceramic groups established according to provenance criteria. The studies of technology and provenance have been performed following an archaeometric approach, using neutron activation analysis, petrographic analysis, X‐ray diffraction and scanning electron microscopy. The results have revealed the existence of two different models. On the one hand, southern Italy seems to exhibit a more organized pottery production, which follows a Mycenaean‐like technology, while in central Macedonia production is probably more varied, being based in part on the technology of the local tradition.     

Production Technology for Copper‐ and Cobalt‐Blue Vitreous Materials from the New Kingdom Site of Amarna—A Reappraisal*

Previously published data on the chemical compositions and microstructures of copper‐ and cobalt‐blue frit, glass and faience from the New Kingdom site of Amarna in Egypt ( Shortland 2000 ) are summarized. The data are then used to infer the raw materials and processes employed in the production of these vitreous materials. The results suggest that crushed quartz pebbles were the source of the quartz for all the materials, but that different sources of alkali, both natron and a range of plant ashes, were used in the production of each material. It seems probable that the cobalt‐rich alum colorant was pre‐treated before use by precipitating cobalt hydroxide from a solution of the alum by the addition of natron. It is further hypothesized that cobalt‐blue glass was produced by melting the cobalt‐blue frit together with additional plant ash and possibly quartz. Finally, it is suggested that, in glazing the cobalt‐blue Variant D faience first produced in the 18th Dynasty, the efflorescence or application method was selected according to object type.