Isotope-geochemical and mineralogical-petrographic characteristics of the pergamon altar marble

Abstract We report preliminary results of our provenance study of marble from the Telephos Frieze of the Pergamon altar. The emphasis here is on the stable isotope geochemistry of marble. The obtained δ(13)C values (2.4 to 3.5‰) vary insignificantly. However, the δ(18)O values give two clusters. The isotopically light marbles (close to -9.5‰) derive from panels 1-8 and the heavy marbles (-3.5 to -1.0‰) derive from panels 11-50. Mineralogical, petrographic and geochemical investigations (accessory minerals, grain size distribution, rare earth elements) further refined the marble characteristics. In spite of certain differences observed (grain size distributions, isotopy and contents of certain elements) for the two marble groups, the present data support a common provenance. So far, east Aegean islands and the Marmara region are favored.     

ESR spectroscopy as a tool for identifying joining fragments of antique marbles: the example of a pulpit by Donatello and Michelozzo

ESR spectroscopy is one of the physicochemical techniques used to characterize archaeological white marbles and obtain information about their quarries of provenance. This is done by measuring selected spectral features of the Mn(2+) impurity ubiquitously present in marbles and developing a statistical classification rule from the variable vectors measured for a significant number of samples of known provenance (the quarry database). Now we show that the overall variability exhibited by the same spectroscopic features decreases rapidly with the linear dimensions of the sampled block and can be used to distinguish fragments belonging to the same piece of stone from those simply originating from the same quarry. Application of the method to the seven marble panels of the Donatello pulpit in Prato (Tuscany) shows that they have all been cut from the same single block and their different degradation must be ascribed to differential weathering and to the different conservation treatments undergone in the past. The limits and possible drawbacks of the method are also discussed.     

Petrographic characterization and provenance determination of the white marbles used in the Roman sculptures of Forum Sempronii (Fossombrone,Marche, Italy)

The Roman municipium of Forum Sempronii (Fossombrone, Marche) was located along the ‘Via Consolare Flaminia’, in the stretch of road where it ran along the final sector of the valley of the River Metauro (Mataurus). The ancient colony of Forum Sempronii, which is cited by Strabo, Pliny, and Ptolemy, was found in the second century BC, probably on the site of an earlier community and its activity continued until the end of the fifth century AD. During ancient and more recent archaeological excavations, many fragments of coloured stones and marbles, and some white marble sculptures have been unearthed. In this paper, we report the results of the provenance identification of the white marbles used for the sculptures found in the archaeological site of Forum Sempronii and now displayed at the local archaeological museum. The determination of the source origin of the white marbles used for the sculptures has been established by mineralogical-petrographic and geochemical analyses. Microscopic study of thin sections together with carbon and oxygen stable isotope ratios indicate that more than one type of white marbles was used: Pentelikon, Lunense, and Thasian.     

The use of electron spin resonance spectroscopy for determining the provenance of classical marbles

The possibility of identifying the provenance of classical marbles and solving related questions, such as the joining fragments problem, via electron spin resonance spectroscopy has been reexamined. The method is based on characterization of the Mn²⁺ impurity ubiquitously present in marbles. Six different, although correlated, spectroscopic variables, such as intensity, linewidth, metal hyperfine splitting and others have been measured, together with some petrographic properties, for over 500 samples belonging to 14 different Italian, Greek and Turkish quarrying sites. The work, still in progress, is aimed to establish a marble database including all the historically relevant sites within the Mediterranean basin. The experimental data matrix has been analyzed with the aid of multivariate statistical techniques, primarily linear and quadratic discriminant analysis, and the ability of the method to classify correctly unknown samples has been estimated through standard techniques (resubstitution, jackknife), but also employing control “unknown” samples. The essential result is that, although the all-variables approach may describe the data set very accurately, the predictive power is due to four variables only, which are a suitable combination of spectroscopic and petrographic information. In this way 82.4% of the control samples could be assigned correctly, whereas inclusion of additional variables in the classification rule may result in substantially poorer performance. The conclusion is that ESR spectroscopy, although not providing a complete and general solution for the marble provenance problems, is probably, at the moment, the most developed methodology for identifying marbles. Its results, coupled with artistic historical information, deal correctly with a number of relevant archaeometric problems.     

Roman Coarse Ware from Bavaria, Austria and Northern Italy

This interdisciplinary study focuses on a specific type of Roman coarse ware that was widely distributed in Bavaria, Austria and northern Italy during the 1st half of the 1st century AD. Various physical methods were applied to study the provenance of this characteristic marble tempered blackware and to assess its production techniques. The blackware found in large numbers on the Auerberg and at other sites in southern Germany can be identified as imported from East Tyrol, Austria.     

Evaporation rate of PTFE liquid marbles

Liquid marbles are hydrophilic liquid drops encapsulated with a hydrophobic powder. They behave as micro-reservoirs of liquids able to move rapidly without any leakage and are promising candidates to be applied in genetic analysis where 2D microfluidics and lab-on-a-chip methods are used. The manipulation of liquid marbles using gravitational, electrostatic and magnetic fields were recently investigated. In this work, we determined the evaporation rates of PTFE marbles formed by encapsulating PTFE micropowder on a water droplet in a closed chamber where relative humidity and temperature was kept constant. Evaporation rates of PTFE marbles were compared with the rates of pure water droplets in terms of evaporation resistance, ? parameter and it was found that PTFE marbles have longer life-time than water droplets so that ? values were found to increase regularly from 0.365 to 0.627 with the increase of RH of the evaporating medium. The barrier effect of PTFE microparticles at the water-air interface was more effective when water was evaporating slowly. PTFE water marbles have life-time of 26-60 min to retain their spherical shape under normal atmospheric conditions which is suitable for many promising applications in microfluidics, genetic analysis, electromagnetic actuators and valves.     

Ultraviolet-Light–Triggered Coalescence of Liquid Marbles for Multistep Microreactions

Liquid marbles show promising potential for application in the microreaction field. The efficient and precise approach for the remote coalescence of liquid marbles is desirable. Herein, the ultraviolet-light–induced wettability transition of TiO₂ nanoparticles is exploited to develop an ingenious approach for efficient and controlled coalesce of contacting liquid marbles containing separate reagents. This approach is generic and provides ideas for the on-demand initiation of multistep microreactions inside liquid marbles.     

Diagnostic analysis of stone materials from underwater excavations: the case study of the Roman archaeological site of Baia (Naples,Italy)

This work belongs to the framework of the national research project “COMAS” (Planned COnservation, “in situ”, of underwater archaeological artifacts), funded by the Italian Ministry of Education, Universities and Research (MIUR), concerning the submarine archaeological area of Baia (Naples, Italy). The site includes remains of the ancient cities of Baiae and Portus Iulius, which, since the 4th century AD, started to be submerged because of the bradyseism phenomenon. The work aims to the characterization of four different types of stone materials collected from the site, specifically marbles, limestones, ignimbrites, and bricks, in order to investigate their state of conservation. In particular, specimens were sampled from some masonry structures and pavement slabs (opus sectile) in a specific area of the submerged site, called “Villa a Protiro”. In order to characterize archaeological samples from a mineralogical-petrographic point of view, polarized optical microscopy and X-ray diffraction analyses were carried out, while to assess their conservation state, the surface colonization by biodeteriogen agents and their interaction with the substrate were studied through observations under a stereomicroscope, scanning electron microscopy and Fourier transform infrared spectroscopy. Marble and limestone samples revealed an intense bioerosion phenomena, attributable to epilithic and endolithic forms, particularly boring sponges. On the contrary, ignimbrites suffer a lower degree of biological colonization related to the activity of other species, such as serpulids and bryozoans. In bricks, biocolonisation is correlated to the type of temper used in the artifact, the quartz pastes having a greater susceptibility to biological attack than the volcanic ones.     

Composition,Luminescence, and Color of a Natural Blue Calcium Carbonate from Madagascar

Concerning the transparent blue calcite crystals of blue marble from Madagascar, this work suggests that their cavities, accessorial quartz, and marble stress textures do not provide unambiguous characterization of the blue color compared to other white marbles. It is suggested that the presence of stronium (～850 ppm), barium (～18 ppm), vanadium (～10 ppm), and nickel (～2 ppm) might be considered influential chromophores for the blue color. Blue marble aliquots were characterized to determine their mineralogical, textural, and chemical composition to elucidate luminescence spectra and the causes of the blue color by use of different techniques.     

Provenance determination of prehistorical pottery from Oshima Island belonging to Izu islands (Tokyo,Japan) using X-ray fluorescence spectrometry

A total of 41 pottery shards originating in the Jomon period (14000–300 BC) and Yayoi period (300 BC–250 AD) were excavated from the Shimotakabora site on Oshima Island of the Izu islands (Tokyo, Japan). X-ray fluorescence spectrometry was used to determine the chemical composition (10 major oxides and 12 minor elements) of the potteries to identify the potteries' provenance, that is, local or nonlocal product. The calibration curves were drawn by synthetic standards prepared from a mixture of chemical reagents containing analytes, which presented good accuracy and reproducibility by analysis of the geochemical references. The pottery samples were classified by multivariate statistics such as principal component analysis and cluster analysis based on their chemical composition. Additionally, the X-ray fluorescence results were compared with geochemical data from Oshima Island using scatter diagrams. The pottery provenance was identified by their classification. This provenance estimation indicates that 37 of the 41 potteries were brought to Oshima island from Japan's main island, Honshu, in the prehistoric age.     

Significant findings concerning the production of Italian Renaissance lustred majolica

In the present paper the main results obtained, over a period of more than ten years, from a series of studies concerning the characterization of Italian Renaissance lustred majolicas (from Gubbio and Deruta, Umbria, Italy) are presented. Lustre decoration is a well-known technique, consisting in the application of a thin metallic iridescent film, containing silver and copper nanoparticles, over a previously glazed ceramic object. The technique had its origin in Persia (IX century), was imported by Moorish in Spain, and then developed in central Italy during the Renaissance period. Numerous analytical techniques (among which, ETASS, XRD, UV–Vis, SEM-EDX) have been employed for the characterization of lustred ceramic shards, allowing one to acquire information on both lustre chemical composition and nanostructure. In this way it was shown how some technological parameters, such as the firing conditions, are mandatory to obtain the final result. The presence of a specific marker of the lustre Italian production, i.e., cosalite (Pb₂Bi₂S₅), has been also highlighted. From the study of the ceramic body composition (by means of XRD and ICP-OES and in particular of chemometric techniques) acquired on more than 50 ceramic shards it was possible to discriminate between Deruta and Gubbio production, in this way allowing one to assign objects of uncertain provenance to a specific site. Finally, the most interesting results obtained studying excellent lustred masterpieces from Renaissance belonging to important museums are here presented. In particular, with the use of nondestructive techniques (PIXE, RBS, and portable XRD), the production of Mastro Giorgio Andreoli from Gubbio was investigated. By means of the same analytical approach, one of the first examples of lustre in Italy (the famous Baglioni’s albarello) was examined, and the controversial question of its attribution to Italian production was scientifically faced.     

White and some colored marbles as alternative radiation shielding materials for applications

ABSTRACT

In this paper, the radiation shielding parameters such as linear attenuation coefficients (LAC, µ), mass attenuation coefficients (MAC, µ/ρ), effective atomic numbers (Z_eff), effective electron densities (N_eff), half value of layers (HVL), mean free paths (MFP) and buildup factors (exposure (EBF) and energy absorption (EABF)) were investigated for cream (M1), pink (M2), white (M3), maroon (M4) and green (M5) marbles. Attenuation coefficients were measured in the energy region 31.18–661.66 keV photon energies. The values of Z_eff and N_eff were then calculated using these coefficients with logarithmic interpolation method, and HVLs and MFPs were calculated using the values of LAC of marble samples at the same photon energies. The experimental results were compared with the theoretical values obtained from WinXCom program, and good agreements were observed between the experimental and theoretical results. HVLs and MFPs of all marble samples were compared with those of some concretes, glasses and commercial radiation shielding glasses (SCHOTT Co.). The studied marbles were better radiation shielding materials than standard shielding concretes due to lower HVL and MFP values lower than the ordinary concrete. Finally, EBFs and EABFs of the marbles were calculated in the energy region 0.015–1?MeV up to penetration depths of 40 mfps by Geometric Progression method (G-P), and the results were discussed in terms of photon energies and chemical compositions of the marbles.     

An integrated Raman and petrographic characterization of Italian mediaeval artifacts in pietra ollare (soapstone)

Ten fragments of pots made by pietra ollare (basic and ultrabasic metamorphic rocks belonging to greenschist facies) found in the archaeological site of Crocetta di Sant'Agata Bolognese (Bologna, Italy) have been studied to characterize them and to define their provenance. The fragments, dated between the 9^th and 10^th century AD, show traces of blackening from fire, indicating the use of these findings as pots by fire. The extensive use of a non‐destructive technique, Raman spectroscopy, in both laboratory and portable forms, for the provenance analysis of pietra ollare artifacts has been evaluated. Micro‐Raman spectroscopy was used for a detailed study of the main components, to identify the secondary minerals and to study the distribution of the mineral phases in the samples. The samples show schistose texture, are fine grained and consist mainly of talc and chlorite, and subordinate carbonates, oxides and serpentine. Olivine is rare. Based on the mineralogical composition, the material can be defined as chlorite and carbonate talc‐schist. Our samples of pietra ollare may be assigned to chlorite and magnesite‐bearing talc‐schists. The alpine areas of origin of this lithotype are Valtellina, Valchiavenna and Val Bregaglia. In particular, we can hypothesize that the origin of these findings is Valchiavenna, which had great commercial importance in the Middle Ages. Further measurements, obtained with a portable Raman spectrometer, directly on a quarry near Chiavenna, support our hypothesis. Copyright © 2013 John Wiley & Sons, Ltd.     

Classification of ancient Etruscan ceramics using statistical multivariate analysis of data

About one hundred Etruscan ceramic shards dating from the VIII to the IV century BC and coming from the archaeological excavation at Pian di Civita in Tarquinia (central Italy) have been analyzed by inductively coupled plasma optical emission spectrometry and flame atomic emission spectrometry in order to settle their provenance and to acquire knowledge about the ceramic production technology. The examined shards belong to the class of the depurata pottery, a fine ware produced in Tarquinia over a long period, and are representative of different sub-classes. The samples have been analyzed for fifteen elements (Ca, Al, Mg, Fe, Ti, Cr, Cu, Ni, Zn, Mn, Zr, Sr, Na, K and Rb). The data acquired have been treated by multivariate analysis techniques such as principal component analysis and Kohonen artificial neural networks. Most of the analyzed shards have been locally produced as belonging to a unique large group. A continuity in usage of both choice of materials and technology has been recognized. PACS 02.50.Sk; 81.05.Mh; 82.80.-d     

Raman identification of natural red to yellow pigments: ochre and iron‐containing ores

Red and yellow natural (roasted) pigments have been used for millennia. This paper reports on the Raman characterization of about 50 pigments of the Ôkhra ‘Mathériauthèque’ collection from different origins: violet, red, orange, apricot, yellow ochre, Umbrian and Siena earths from France (Puisaye, Ardennes, Vaucluse), Italy (Siena, Sardinia, Venice, etc.), Germany, Sweden, Cyprus and India (Madras). Comparison is made with ‘Bengara’ Japanese pigments. Goethite is the chromophore of yellow pigments, and haematite (sometimes with magnetite) that of red ochre and earths. Umbrian pigment (‘Terre d'Ombre’) contains additional manganese oxides. Color shades are related to the content of secondary phases: iron oxides (haematite, goethite, magnetite), quartz, gypsum and anhydrite, calcite, dolomite, alums (jarosites), and to the Fe/M substitution in the haematite structure. The set of secondary phases can be used to confirm a provenance signature (Supplementary Material available). Copyright © 2008 John Wiley & Sons, Ltd.     

Sugaring marble in the Monumental Cemetery in Bologna (Italy): characterization of naturally and artificially weathered samples and first results of consolidation by hydroxyapatite

The so-called sugaring of marble is a very common degradation phenomenon, affecting both historical monuments and modern buildings, which is originated by environmental temperature fluctuations. Thermal cycles are indeed responsible for micro-cracks formation at the boundaries between calcite grains, so that marble is subjected to granular disintegration and can be reduced to a sugar-like powder of isolated calcite grains by just the pressure of a finger. Since no effective, compatible and durable treatment for sugaring marble consolidation is currently available, in this paper a novel consolidating treatment recently proposed for limestone, based on the formation of hydroxyapatite inside the stone, was investigated for weathered marble. To test the new treatment on suitably decayed marble samples, some naturally sugaring marbles from the Monumental Cemetery in Bologna (Italy, nineteenth century) were firstly characterized by scanning electron microscope (SEM), mercury intrusion porosimetry (MIP) and ultrasonic pulse velocity (UPV) measurement. Then, artificially weathered samples were produced by heating fresh Carrara marble samples at 400 °C for 1 h. The effects of artificial weathering were characterized using the same techniques as above, and a very good agreement was found between microstructure and mechanical features of naturally and artificially weathered samples. Then, the hydroxyapatite-based treatment was tested on the so-obtained artificially weathered samples, and the treatment effects were characterized by UPV, MIP and SEM equipped with energy dispersive spectrometry and Fourier transform infrared spectroscopy. The hydroxyapatite-based treatment exhibited a remarkable ability of restoring marble cohesion and a good compatibility in terms of modifications in pore size distribution, which leads to regard this treatment as a very promising consolidant for weathered marble.     

Cathodoluminescence spectra of diamonds in UHP rocks from the Kokchetav Massif, Kazakhstan

We propose to investigate the diamonds from the Kokchetav Massif, northern Kazakhstan, which is the best example of diamond-eclogite facies metamorphism, using cathodoluminescence (CL) techniques. CL spectra measurements of diamonds from garnet-pyroxene-quartz rocks and dolomitic marbles, made at 80 K, revealed peaks at 2.156, 2.463, and 3.188 eV and a broad band at 2.72-2.80 eV. Panchromatic and monochromatic diamond images analysed by CL reveal concentric zones of variable luminescence. This indicates that the diamond crystals grow during several metamorphic stages under ultra high pressure (UHP) metamorphism conditions. The inhomogeneous broadening and lower 2.156 eV ZPL peak suggests the presence of a higher concentration of defects and stresses in the rim compared to the core.     

Effect of mineralogical and microstructural properties on surface roughness and gloss of some ornamental marbles subjected to polishing process

High surface finish quality of the produced slabs is generally desirable in the stone processing industry. This paper presents the results of an experimental investigation into the effects of mineralogical‐petrographical and chemical variables on the surface roughness and glossiness of some selected ornamental marbles subjected to grinding–polishing processes. For this purpose, a series of grinding–polishing procedures were performed on the slabs of three distinct marble types. Roughness and brightness measurements were carried out on predetermined surfaces of marble samples using a stylus profilometer and a glossmeter, respectively. Thin sections were examined by a polarizing microscope for mineralogical‐petrographical characterization of the studied marbles. Scanning electron microscopy was used to aid in the identification and characterization of the slab surface morphologies at each polishing stage. X‐ray diffraction and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy were used for the determination of mineralogical and chemical compositions of the samples. Mainly because of the differences in textural and chemical compositions, different levels of microroughness and gloss values were observed for the studied marble varieties. The presence of different mineral phases such as the grain (i.e. calcite to calcite) and phase contacts (i.e. calcite to epidote) greatly affected the heterogeneity of the marbles, resulting with different removal mechanisms under the action of abrasive grits. Copyright © 2013 John Wiley & Sons, Ltd.     

Provenance identification of ancient pottery from Hachijojima Island,part of Izu Islands (Tokyo,Japan), using X-ray fluorescence spectrometry

A total of 47 pottery fragments were unearthed in Hachijojima Island, part of the Izu Islands (Tokyo, Japan). Among these samples, 36 found in the Kurawa site had designs resembling pottery dating back to the Jomon period (14,000–300 BC) distributed throughout Japan's main island, Honshu; five samples from the Jomon period found in the Yubama site were “undesigned”; the rest, found in the Yaene site, were undesigned Haji pottery samples dating back to the beginning of the late Kofun period (490–549 AD). X-ray fluorescence spectrometry (XRF) was used to determine the chemical composition (in terms of 10 major oxides and 12 minor elements) of the samples to identify their provenance, that is, local versus nonlocal. For this purpose, a portion of each pottery fragment was processed to obtain a glass bead specimen. The pottery samples were classified by multivariate statistical approaches, including principal component analysis and cluster analysis, on the basis of their chemical composition. Additionally, the XRF results were compared to geochemical data from Hachijojima Island using scatter diagrams. The data thus collected allowed the provenance of the pottery samples to be inferred. In particular, the 36 samples from the Kurawa site were concluded to have been brought to Hachijojima Island from Honshu in prehistoric times, whereas the other samples were concluded to have been manufactured locally.     

The development and limits of freezing tolerance in Acer pseudoplatanus fruits across Europe is dependent on provenance

The effects of fruit maturity, at the time of natural dispersal, on subsequent desiccation tolerance and sub-zero storage was investigated in three lots of Acer pseudoplatanus (sycamore) collected from northern to southern Europe. Fruits from the native plant distribution range in Italy had significantly higher desiccation tolerance (0.16 g water per g DW) than those from England (0.30) and Norway (0.50), confirming that the maximum potential desiccation tolerance in sycamore exceeds that of the recalcitrant type. In contrast, the unfrozen water content varied only slightly between seedlots, but systematically reduced with development (0.35 to 0.27 g water per g DW). Maximum survival (60 percent fruit germination) of seven days sub-zero temperature storage coincided with drying the Italian fruit lot to c. 0.2 g water per g DW followed by holding at -20 degree C, above the onset temperature for freezing, or at -196 degree C (liquid nitrogen). Fruit survival was much lower in the Italian fruits when held at this water content and -70 degree C, and in all other combinations of water content, temperature and fruit lot provenance. As the risk of nucleation in partially dried fruits held at -20 degree C is high, we recommend sycamore fruits are cryopreserved for long-term conservation.