Hundreds of large, shaped and perforated amber beads excavated from two Middle Sicán elite shafttombs at Huaca Loro on the northern coast of Peru represent the first scientifically documented case of amber use in prehispanic South America. Amber was highly valued and formed a key component of Sicán sumptuary good production. This paper describes the analytical procedures and archaeological and botanical background for source identification and cultural understanding of amber beads found on pectorals, necklaces and gold alloy objects. Samples were initially identified by XRD and FT-IR microscopy, followed by a more detailed and conclusive analysis using pyrolysis GC-MS. Radiocarbon dating points to a minimum age of 50,000 years. Results were compared with amber from known sources in the New World. Various lines of evidence suggest that the amber was derived from a heretofore unknown source, probably an ancient species of Hymenaea, possibly related to H. oblongifolia (family Leguminosae) occurring today in upper Amazonia.

Many ancient Chinese bronze mirrors have a smooth patina. An ingress of corrosion to a depth of approximately 100 μm is found beneath the patina. The corrosion selectively replaces the Cu-rich α phase leaving the Sn-rich σ phase intact. Previous work by x-ray diffraction has shown that the a-phase replacement product is poorly crystallized or nanocrystalline SnO2. Transmission electron microscopy was employed to further characterize the replacement product in both ancient mirror and replication samples. Nanocrystalline SnO, in the form of small spheroids has been found. Remnants of an original alloy phase appear to be interspersed with the tin oxide.

The easy determination of the chemical composition of the plastic components of museum objects has been identified as a critical requirement for the proper preservation and treatment of museum objects with plastic components. To date, chemical identification has been done by wet chemical spot tests applied directly on the object, or by spot tests or instrumental techniques such as IR spectroscopy on samples excised from objects. These methods are not satisfactory. Spot tests are neither comprehensive nor unambiguous, and instrumental techniques are not convenient since the instruments are generally located in analytical laboratories remote from the museum collections. This paper describes the use of a portable FTIR spectrometer with a fiber optic sampling probe to acquire mid-IR reflectance spectra from plastics in museum objects. The technique is non-destructive and is performed on-site at the museum collection. Results will be described with an emphasis on the practicalities of transporting the spectrometer and accessories, and collecting and interpreting spectra.

Common processes used in glazed ceramic production often result in a glaze with a heterogeneous microstructure. Heterogeneities may be due to residual batch materials, intentionally added colorants and opacifiers and/or the products of devitrification and phase separation. To study the effect of heterogeneities in the corrosion process, dynamic imaging microellipsometry was used in-situ in aqueous solutions to measure spatially and temporally resolved changes in the surface of glasses (model glazes). The measurements showed increased durability near inclusions. Residual stress fields surrounding the heterogeneities influenced the results. Decoupling of chemical and mechanical factors causing this increased durability was not possible.

The use of totally non-destructive techniques such as image spectroscopy for diagnosing paintings makes it possible to obtain a large amount of spectral data that provides information concerning the composition of works of art. Here, we stress how statistical treatments, such as principal component analysis (PCA), applied to 2-D data, can contribute to a better knowledge of the work of art itself and of the distribution of the materials that constitute it.

Laboratory tests, as well as applications to actual paintings, will be presented and discussed.

In the past, many attempts have been made to determine the degree of polymerization (DP) of cellulose in ligneous pulps or papers. Frequently, the methods employed caused severe depolymerization of the cellulose.

The present paper provides a detailed procedure of DP determination of cellulose for both lignin-free and ligneous papers. The proposed method is based on viscosity measurements of cadoxen solutions of cellulose. Prior to dissolution in cadoxen, ligneous samples are partially delignified by a modified chlorite method, under conditions preventing any substantial depolymerization of cellulose. Results of preliminary experiments carried out on groundwood newsprint papers provide strong evidence of reliability of DP values so determined.

We report on the surface microchemistry of a Roman iron object and of a Roman lead pipe ‘fistula’. The original patina of the iron sample consists mainly of oxidic phases whose lateral distribution is imaged with a submicron spatial resolution. Metallic iron in the bare surface is covered with a Fe(lll)-Fe(ll) oxidic layer which is several times thicker than in a modern ferritic steel. We find that the presence of a flux minimizes lead oxidation in the joint of the fistula as well as in comparison, ‘modern’ lead soldered samples. In one of these comparison samples the lateral distribution of the chemical species present is imaged with a spatial resolution of about 1000 Å.

To evaluate the performance of inductively coupled plasma mass spectrometry (ICP-MS) in determining ceramic provenance, we analyzed 60 elements in 30 ceramic artifacts from six a priori groups from west Texas-southwestern New Mexico. Discriminant function analysis of the ICP-MS elemental data classified all members of the six a priori groups without error. In repeated analyses using 80% of the data as a training set, overall 75% of the withheld specimens were properly classified. Lead isotope ratios, also measured on the ICP-MS, provided an independent partial discrimination between the groups. The results of this study demonstrate that ICP-MS provides multi-element and lead isotopie characterization of archaeological ceramics suitable for provenance determination. ICP-MS is a rapid, in-house, and relatively inexpensive technology and thus is a reasonable alternative to neutron activation analysis (NAA) for compositional studies of archaeological ceramics.

The authors studied a suite of fragments of corroded bronzes from the Tienma-Qu Cun site, a Western Zhou city and cemetery complex dating from ca. 1000 to ca. 650 B.C‥ Conventional metallographic techniques were used along with scanning electron microscope, electron microprobe and x-ray diffraction. The bronzes are very varied in structure and composition. Most are cast, moderate-tin bronzes, but some are high or low in tin or lead. A few show a worked and annealed structure, and some of the cast bronzes were also heat treated (possibly by use as cooking pots). corrosion patterns also vary greatly, from almost uncorroded to total mineralization. Periodic and esquential corrosion phenomena were detected, as well as patination applied when the bronzes were made. We had hoped to be able to ascertain the causes of the different penetration of corrosion in these samples, but that must remain for future work.

New metallurgical and ethnographic observations of the traditional manufacture of specular high-tin bronze mirrors in Kerala state of southern India are discussed, which is an exceptional example of a surviving craft practice of metal mirror-making in the world. The manufacturing process has been reconstructed from analytical investigations made by Srinivasan following a visit late in 1991 to a mirror making workshop and from her technical studies of equipment acquired by Glover in March 1992 from another group of mirror makers from Pathanamthita at an exhibition held at Crafts Museum, Delhi. Finished and unfinished mirror from two workshops were of a binary, copper-tin alloy of 33% tin which is close to the composition of pure delta phase, so that these mirrors are referred to here as ‘delta’ bronzes. For the first time, metallurgical and field observations were made by Srinivasan in 1991 of the manufacture of high-tin ‘beta’ bonze vessels from Palghat district, Kerala, i‥e of wrought and quenched 23% tin bronze. This has provided the first metallurgical record for a surviving craft of high-tin bronze bowl making which can be directly related to archaeological finds of high-tin bronze vessels from the Indian subcontinent and Southeast Asia. New analytical investigations are presented of high-tin beta bronzes from the Indian subcontinent which are some of the earliest reported worldwide. These coupled with the archaeometallurgical evidence suggests that these high-tin bronze techniques are part of a long, continuing, and probably indigenous tradition of the use of high-tin bronzes in the Indian subcontinent with finds reported even from Indus Valley sites. While the source of tin has been problematic, new evidence on bronze smelting slags and literary evidence suggests there may have been some sources of tin in South India.

Various methods were used to produce steel in early Islamic times. According to early Islamic texts, three methods are described for indirect production of steel (fuladh). The methods are solid-state carburization of wrought iron, partial decarburization of cast iron or a high carbon steel, and co-fusion of cast iron with wrought iron. Evidence from a metallurgical workshop at Merv, dated to the ninth-early tenth century A.D., provides an illustration of the co-fusion method of steel production in crucibles. The primary investigations of the crucibles are presented. The crucible slag was found to contain droplets of cast iron and steel and the crucible fabric contains mullite.

European accounts from the 17th century onwards have referred to the repute and manufacture of “wootz’, a traditional crucible steel made especially in parts of southern India in the former provinces of Golconda, Mysore and Salem. Pliny's Natural History mentions the import of iron and steel from the Seres which have been thought to refer to the ancient southern Indian kingdom of the Cheras. As yet the scale of excavations and surface surveys is too limited to link the literary accounts to archaeometallurgical evidence, although pioneering exploratory investigations have been made by scholars, especially on the pre-industrial production sites of Konasamudram and Gatihosahalli discussed in 18th-19th century European accounts. In 1991–2 during preliminary surveys of ancient base metal mining sites, Srinivasan came across unreported dumps with crucible fragments at Mel-Siruvalur in Tamil Nadu, and Tintini and Machnur in Karnataka and she collected surface specimens from these sites as well as from the known site of Gatihosahalli. She was also given crucible fragments by the Tamil University, Tanjavur, from an excavated megalithic site at Kodumanal, dated to ca 2nd c. Bc, mentioned in Tamil Sangam literature (ca 3rd c. BC-3rd c. AD), and very near Karur, the ancient capital of the Sangam Cheras. Analyses of crucible fragments from the surface collection at Mel-Siruvalur showed several iron prills with a uniform pearlitic structure of high-carbon hypereutectoid steel (∼1–1.5% C) suggesting that the end product was uniformly a high-carbon steel of a structure consistent with those of high-carbon steels used successfully to experimentally replicate the watered steel patterns on ‘Damascus’ swords. Investigations indicate that the process was of carburisation of molten low carbon iron (m.p. 1400° C) in crucibles packed with carbonaceous matter. The fabric of crucibles from all the above mentioned sites appears similar. Preliminary investigations on these crucibles are thus reported to establish their relationship to crucible production of carbon steel and to thereby extend the known horizons of this technology further.

Amalgam gilding was one of the most common techniques for the gilding of metalwork before the invention of electroplating. Its silver equivalent, amalgam silvering, was executed in the same manner, by applying a paste of silver amalgam and mercury to a copper alloy object and subsequent heating to form a diffusion bond between substrate and plating and to evaporate the excess mercury, followed by burnishing of the surface. The technical know-how was readily available. However, even though many medieval and post-medieval European metal objects were silver plated, only a few coins and small objects like medieval decorative mounts and horse trappings, and post-medieval astronomic instruments have been reported as examples of amalgam silvering. The technique was also used in China in the 3rd-1st century BC. Should we assume that there are many more amalgam silvered objects waiting to be discovered, as has been suggested? This paper investigates silver plated objects from 3rd century BC Chinese belt hooks to 18th century French decorative art and compares the analytical evidence with original silvering recipes and replication experiments, which showed that with amalgam silvering satisfactory results were far more difficult to achieve than with fire-gilding. It was found that the presence of mercury in XRF analyses of silver plated surfaces did not necessarily identify amalgam silvering, and that some allegedly amalgam silvered objects may in fact have been plated with silver chloride based electrochemical replacement silvering pastes.

An excavation at Khirbet edh-Dharih implemented by the Institut Français D'Archaéologie du Proche-Orient brought forth a few archaeometallurgical remains such as lumps of bronze, slags, and refractory ceramic fragments. Khirbet edh-Dharih is located in Jordan, near the Feinan area at Wadi Arabah. The Feinan area is well known as a major supplier of copper in the Near East's history from the Chalcolithic to the Roman period. The remains from Khirbet edh-Dharih were dated from the Iron Age II, and they are pointing to a workshop for further treatment of copper from Feinan. Khirbet edh-Dharih is the first bronze melting site excavated in the Feinan copper district.

The study of 4 metallic artifacts from the Medium Grijalva, two bells, a bipointed awl, and a needle, and one bell from Huehuetenango, Guatemala, were studied using of elemental analysis by flame atomic absorption spectroscopy (FAAS), metallographic examination and typological classification. Several problems arose, including the need to have a clearer definition of bell types, better knowledge of the technology of production of needles and awls, and problems with the Cu-Pb alloys, especially if a how high a lead content forms a Cu-Pb alloy solution.

Early analyses made of bells and copper artifacts from the Maya area, Western Mexico and Southwest USA shows variable but important amounts of lead. The Cu-Pb phase diagram shows a monotectic reaction where the metals have poorcapability of alloying or mixing, forming a eutectic at very low lead concentrations. Few metalographic studies of these alloys are reported in papers about historic metals. However, some ternary Cu-Pb alloys are found in recent literature. Does the low arsenic content as in the analysis of the Cu-PbMayan bells influence the properties of the alloys? The importance of the distribution of types of bells made of Cu-Pb could clarify possible cultural connections and trade among the Maya area, western Mexico and southwest United States. The possible introduction of metallurgy from and trade with South America makes this search of even more importance.

A large amount of smelting slags, tuyeres and curved refractory materials used during pyrometallurgical activities have been found at Tharros (western-Sardinia, Italy) during an excavation stratigraphically related to the Phoenician-Punic period (VI-IV BC). The microchemical structure of the vitrified end of tuyeres and of the thick fragments of the smelting furnaces, has been studied by means of scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS). The results indicate that these materials can be associated with an iron smelting process. Furthermore, the temperature and duration of the smelting process has been estimated from the study of vitrification process and penetration depth of vitrification of the tips of some tuyeres combined with the study of pieces of clay taken from a unverified fragment of a tuyere and subjected to different thermal treatments under reducing atmosphere.

Thirty-four gold solidi coins and two pairs of gold/jewel earrings were discovered at an archaeological site in Jordan, Tell Nimrin. The coins have stamped images of six late Roman/early Byzantine emperors who reigned from 346 AD to 518 AD. These objects were analyzed by X-ray radiography, SEM/EDS and density measurements to find the gold content for comparison with other coins ofthat period to support their authenticity and to see whether debasement of coinage had occurred. The average surface gold content was found by EDS to be 98.1 wt %--typical of the period--but the bulk content calculated from density values was 1 to 3 wt % lower. The reason offered is that when a molten gold-copper or gold-silver alloy solidifies, the region in contact with the blank coin mold freezes first and is gold-enriched. Small “silvery” specks were observed on the obverse (”heads”) side of several coins and found by EDS to be Os-Ir-Ru alloys, which come from placer mining and indicate that the gold also came from placer mining.

An overview of the development of the materials used for surgical knives is presented. Because early surgical tools are hard to recognize in terms of specific function, unless they are found in context they are difficult to identify. A rare exception is the collection of Roman surgical implements found in Pompeii. In order to demonstrate the level of technology typical ofthat time, metallographic study has been performed on an object identified as a Roman surgical probe similar to those found in Pompeii. The composition, microstructure, and fabrication technology for this object is discussed in relation to its functional use.

Long-distance trade in obsidian from sources in the southwest Pacific has been well-documented for the Lapita culture complex, beginning about 1600 BC. Analyses of obsidian artifacts from recent excavations at Bukit Tengkorak in southeastern Sabah (Borneo, Malaysia) indicate the use of obsidian from multiple sources in Melanesia as early as the 5th millennium BC. The archaeological presence of obsidian, up to more than 3500 km from its source, is the surviving evidence of what was almost certainly the longest Neolithic trade route in the world. In addition, these results indicate that long-distance trade networks existed in Indonesia at least 2500 years prior to the Lapita culture, and strengthen hypotheses of its origins in southeast Asia.

European explorers and traders, on their arrival in North America, found the aboriginal peoples willing to exchange furs and other goods for European-made metal objects and glass beads, the remains of which may be found at archaeological sites. Specific trade goods, including multi-coloured or curiously shaped glass beads that are visually distinctive, are used as chronological markers by archaeologists. Most of the single coloured, mainly blue or opaque white beads are very common and cannot be visually, chronologically differentiated. Non-destructive analysis (INAA) of turquoise blue or white beads from known-age archaeological sites in Ontario has revealed chemical changes in glass manufacturing compositions over time. This allows these otherwise nondescript, single coloured beads to be used as chronological and trade markers. Although the turquoise beads were always coloured by Cu, the white beads employed different opacifiers over time. First came Sn-rich beads (early to late 17th century); then Sb-rich beads (late 17th century to mid-19th century); finally As-rich beads (very late 18th century to early 20th century) and even F-whitened beads (19th century to 20th century). Within each major group, it appears that changes in glass making recipes may be found using the Na, K, Ca, Al and Cl contents. Therefore, chemical analysis of white glass trade beads may be as profitable as chemical analysis of turquoise blue trade beads in establishing chemical chronologies.