Search Results (7)

The ceramic pastes of ca. 31 samples recovered from the Almaraz archaeological site, located in the south bench of Tagus River, were studied in detail using XRF, micro-Raman and GSDR spectroscopies, as well as the XRD technique. The ceramic sherds could be grouped into six categories, red slip tableware, decorated tableware, yellow slip tableware, grey tableware, common tableware, and handmade pottery. Our studies of the mineralogic composition of the sherds’ body indicate all ceramics were produced locally, using siliceous clays in most cases and calcareous clays in a few ones. Micro-Raman and ground state diffuse reflectance absorption spectroscopy provided useful information regarding the materials used to produce the coloured ceramics: hematite and brookite for the red slip and decorated ceramics, jacobsite or carbon black for the black decoration or grey ceramics. For the yellow slip tableware, a simple engobe rich in yellow clay was used. XRF spectroscopic studies provided the elemental composition of all samples, and biplots of the potassium (K) versus calcium (Ca) contents, normalized to the silicon content of each ceramic paste, clearly show Pliocene and Miocene local clays sources were used to produce most ceramics. Only one sherd can be considered a Lisbon production. Full article

The current work deals with specific investigations on the ceramic fragment samples from the archaeological site of Topolița (Eastern Romania), which is essentially unexplored to date. X-ray diffraction (XRD) has shown that the ceramics contain quartz, berlinite, mica (muscovite), calcite, and opaque minerals, such as hematite. All evidence indicates the use of raw materials with a low limestone content (poor Ca clays) for the manufacture of these ceramics (Ca < 3.6%). The wavelength dispersive X-ray fluorescence (WDXRF) measurements indicated the presence of Al, Si, Fe, Ca, Zn, P, and K. All these data are well correlated with energy dispersive spectroscopy (EDS), which is used as an additional technique of scanning electron microscopy (SEM). Through thermogravimetry and porosimetry, some information have been obtained, with the results being correlated with the chromatic parameters that characterize the samples after burning: Various shades of color (red color with sparkles and partially or totally black interior), differently colored engobes, white pigment encrusted with white color from calcite, gypsum, clays, and quartz, as well as carbon deposits in the pores of the pottery, all specific to the Chalcolithic ceramics from this region. The recorded FTIR spectra of these samples led to the identification of calcite, quartz, gypsum, and aluminum phosphate, present as berlinite in all the pottery specific to this area. In addition, the presence/absence and the amount of specific chemical elements in the white pigments (e.g., calcium, aluminum, phosphorus, silicon, sulfur) could be used as indicative for the identified mineral compounds (XRD and FTIR). Calcite and silica-rich sediments as the primary decoration pigments, have been identified in this case. Full article

The southern island of the Philippines is abundant in silicate minerals, including the province of Lanao del Norte. However, some of these resources in the region are untapped for use as raw materials in the production of various ceramic products for industrial, pharmaceutical, and nanotechnology applications. These could include tiles, sanitary ware, dinnerware, insulating bricks, porcelain, membranes and coatings. Some of the explored minerals are the red clay in the municipality of Linamon, diatomaceous earth in Kapatagan and black cinder in Salvador. It is the aim of this study that these minerals are evaluated in terms of their physical and chemical properties so that these will be used for optimum application. The properties that were determined were their specific gravities, raw and fired surface colors, Atterberg limits, particle size distribution, thermal properties, morphologies and mineralogical compositions. Pellets were formed for each raw material and fired at two temperature levels 1000 °C and 1200 °C to evaluate their physical properties. Linamon red clay has a 38.88% cumulative passing size of 150 µm, and the black cinder of Salvador and diatomaceous earth of Kapatagan have cumulative passing sizes of 96.53% and 60.12% at 150-micron sieve, respectively. The common mineral contents of the three samples are montmorillonite, quartz and andesine. Black cinder fired at 1200 °C has the darkest shade of red with a greasy quasi-submetallic luster. It attained the highest fusion coverage on the platform among the three materials, which makes it a potential supplement or replacement for feldspar in clay-based triaxial materials for ceramic production. The diatomaceous earth has the potential to be a secondary clay content source and a good source of flux for a certain temperature range. Both the red clay and diatomaceous earth were classified as plastic materials that are suitable for brick production, and the red clay is also feasible for pottery production. These are a few of the features of the clay minerals in the region that present suitable properties for application as raw materials in the production of ceramic tiles and hollow ceramic products. Full article

The wall paintings of five Hellenistic tombs in Apulia were analysed using a multi-technique approach to discern the painting techniques used and contextualise them within the phenomenon of Hellenistic tomb painting in Southern Italy. In particular, the question was asked whether technical knowledge played a role in the reception of Hellenistic artistic models and whether this knowledge was present locally. Raman and IR spectroscopies were used to identify pigments, colourants, and binders; light and electron microscopy were used to determine the structural characteristics of the paint layers and recognise the manufacturing technique. Analyses identified a fresco application for the Tomba dei Cavalieri (Arpi) and a dry application for the Canosian hypogea. The palette—typical for Hellenistic tomb painting in Southern Italy, Etruria and Macedonia—was composed of lime (white), charcoal (black), hematite (red), goethite (yellow), and Egyptian blue (blue). In the Tomba della Nike (Arpi), meanwhile, two particularly refined preparatory layers were observed. The palette was enriched with precious cinnabar and madder lake. The colouring components of the root were mixed with clay and K-alum applied on an additional layer of lime. The use of madder lake and a pink background link the painting to the polychrome Daunian pottery, and the contribution of a local workshop to the decoration of this tomb thus seems plausible. Full article

The purpose of this review is to provide a general description of ancient winemaking techniques and wine styles that were most lauded in antiquity, in support of their revival and dissemination today. From the first fully excavated winery, dating from the late fifth to the early fourth millennium BC, the gentle crushing of grapes by foot and the probable absence of maceration indicate that most wines were made with the aim of reducing astringency. The oxidative nature of winemaking would have resulted in rapid browning, so that wines made from red grapes would have had a similar color to those made from white grapes after being aged in clay vats for several years. The difficulty in preventing the wine surface contact with the air would have resulted in biological ageing under the yeast pellicle being a common occurrence. This phenomenon was not considered a flaw, but a characteristic feature of highly prized wines. Dried grapes were used to make sweet wines, which were also highly prized, therefore justifying the construction of dedicated facilities. The addition of boiled juices, salt, resins, mixtures of herbs, spices, fruit juices, flowers, or honey to the wines would have increased their taste pleasantness while improving their preservability and medicinal properties. Indeed, today’s preference for flavored wines with a soft mouthfeel seems to have been representative of the ancient elite consumers. Overall, the technical interpretation of winemaking described in this review will provide solid historical support for the current rebirth of ancient production methods, particularly those using pottery vessels. Full article

The archaeometric study of the “golden slip” ware (second century BCE—fourth century CE) at the site of Barikot (Swat, north-western Pakistan) aimed to define its manufacturing technology and provenance of the raw materials used. For this reason, a multianalytical approach consisting of the microscopic, microstructural and mineralogical analysis of both the golden slip and the ceramic paste was adopted. The slip was found to be composed by platy minerals, microchemically identified as talc and chlorite; their intimate association indicated clearly that they derived from a chlorite-talc schist. This rock is geologically available near the site in the “green stones” lenses within the Mingora ophiolites outcropping in the Swat valley. Due to the use of this stone also for the production of stone tools, it cannot be excluded that the chlorite-talc schist used for the golden slip can be derived from manufacturing residues of the Gandharan sculptures. In order to constrain the firing production technology, laboratory replicas were produced using a locally collected clay and coating them with ground chlorite-talc schist. On the basis of the mineralogical association observed in both the slip and the ceramic paste and the thermodynamic stability of the pristine mineral phases, the golden slip pottery underwent firing under oxidising conditions in the temperature interval between 800 °C and 850 °C. The golden and shining looks of the slip were here interpreted as the result of the combined light reflectance of the platy structure of the talc-based coating and the uniform, bright red colour of the oxidized ceramic background. Full article

Red pottery clay (RPC) was modified using a silane coupling agent, and the modified RPC (mRPC) was then used to enhance the performance of high-density polyethylene-based wood-plastic composites. The effect of the mRPC content on the performances of the composites was investigated through Fourier transform infrared spectrometry, differential mechanical analysis (DMA) and ultraviolet (UV)-accelerated aging tests. After adding the mRPC, a moisture adsorption hysteresis was observed. The DMA results indicated that the mRPC effectively enhanced the rigidity and elasticity of the composites. The mRPC affected the thermal gravimetric, leading to a reduction of the thermal degradation rate and a right-shift of the thermal degradation peak; the initial thermal degradation temperature was increased. After 3000 h of UV-accelerated aging, the flexural strength and impact strength both declined. For aging time between 0 and 1000 h, the increase in amplitude of ΔL* (luminescence) and ΔE* (color) reached a maximum; the surface fading did not became obvious. ΔL* and ΔE* increased more significantly between 1000 and 2000 h. These characterization results indicate that the chromophores of the mRPC became briefly active. However, when the aging times were higher than 2000 h, the photo-degradation reaction was effectively prevented by adding the mRPC. The best overall enhancement was observed for an mRPC mass percentage of 5%, with a storage modulus of 3264 MPa and an increase in loss modulus by 16.8%, the best anti-aging performance and the lowest degree of color fading. Full article