A Possible Natural and Inexpensive Substitute for Lapis Lazuli in the Frederick II Era: The Finding of Haüyne in Blue Lead-Tin Glazed Pottery from Melfi Castle (Italy).

The blue color of glass and ceramic glazes produced in Apulia and Basilicata (Southern Italy) between the 13th and 14th centuries and connected to the Norman-Swabian Emperor Frederick II, has been, for a long time, under archaeometric investigation. On the one hand, it has usually been associated with lapis lazuli, due to the finding of the polysulphide blue chromophores typical of lazurite. Moreover, the observation that the mineral haüyne, which belongs to the sodalite group as well as lazurite, can be blue and/or can gain a blue color after heating, due to the same chromophores, has caused this automatic attribution to be questioned, and also considering that the mineral is characteristic of the rock haüynophyre of Melfi (Potenza, Southern Italy), a location of interest for glass and pottery findings. In this paper, for the first time, several haüyne crystals were found in the blue glaze of a ceramic dish found at Melfi Castle, leading to the hypothesis that, in this case, the local haüyne-bearing source could have been used as the coloring raw material. The discovery was possible thanks to SEM-EDS and Raman analyses that, respectively, highlighted the typical numerous presence of very fine sulphur-based inclusions in the crystals and the characteristic Raman signal of blue haüyne. This study was also focused on the composition of the crystals inclusions, aided by SEM-EDS and Raman maps, since the original very fine pyrrhotite was transformed into Cu and Pb phases (copper sulphates, copper sulphides, and lead oxide) due to reactions with cations that had mobilized from the glaze, while the migration of Si from the glass allowed the transformation of the rim of the haüyne, a silica-undersaturated mineral, into a corona of small euhedral and neomorphic Pb-rich feldspars, a silica-saturated phase.

Non-invasive analysis of reference glass and historical mosaic tesserae by means of reflectance infrared spectroscopy.

Within vibrational spectroscopy techniques, Raman is much more employed than infrared spectroscopy for the study of glassy materials belonging to cultural heritage. This could be due to both a less straightforward interpretation of the spectra and a more difficult application of the technique with portable instrumentations. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) can be exploited in archaeometric investigations because portable and non-invasive. On the other hand, no systematic applications of this technique to historical glasses are found in the literature. This exploratory work reports the DRIFTS investigation of the Corning Archaeological Reference Glasses, widely used as references in the cultural heritage field, and of real case glass samples, with the aim of exploring the potential of this technique to gain information about their composition and alteration. The results, exploiting the association of portable X-ray Fluorescence (pXRF), and, where possible, of EDS microanalyses, are encouraging, setting the samples within a compositional range and highlighting spectral differences for the altered surfaces.

XRF analysis searching for fingerprint elemental profile in south-eastern Sicily tomatoes.

The implementation of analytical techniques able to certify food quality and origin in a fast and non-destructive way is becoming a widespread need in the agri-food sector. Among the physical non-destructive techniques, X-ray fluorescence (XRF) spectrometry is often used to analyze the elemental composition of biological samples. In this study, X-ray fluorescence (XRF) elemental profiles were measured on tomato samples belonging to different geographical areas in Sicily (Italy). The purpose of this investigation was aiming to establish a protocol for in-situ measurement and analysis able to provide quality assessment and traceability of PGI agri-food products, specifically sustaining health safety and self qualifying bio-chemical signature. In detail, sampling was performed in one of the most tomato productive area of south-eastern Sicily (Pachino district), characterised by a relative higher amount of Organic Carbon and Cation Exchange Capacity, and compared with samples from other growing areas of Sicily, falling in Ragusa province and Mt. Etna region. Experimental data were analyzed in the framework of multivariate analysis by using principal component analysis and further validated by discriminant analysis. The results show the presence of specific elemental signatures associated to several characterizing elements. This methodology establishes the possibility to disentangle a clear fingerprint pattern associated to the geographical origin of an agri-food product.

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) as a potential on site tool to test geopolymerization reaction.

Geopolymers, synthesized starting from aluminosilicate precursors activated with alkaline solutions, constitute a class of materials of high interest as potential substitutes of traditional, cementitious, binders. Infrared spectroscopy is one of the routine analytical techniques employed to study these materials and to verify the occurrence of geopolymerization; on the other hand, its portable version working in diffuse reflection is not enough exploited for their characterization. The aim of this work is therefore to assess the potentiality of Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) in the study of geopolymers. The combination of this technique with Principal Components Analysis (PCA) statistical treatment was used to search for criteria able to discriminate the successful products from those which require a correction in their formulation. Mainly, two groups of geopolymers were studied, based respectively on clay sediments and ceramic waste precursors, in the latter case with the possible addition of metakaolin. These samples were studied both after maturation, comprising several variables in their mix-design and curing, and during the first hours of solidification of the slurry. The results allowed to identify the best formulations within the analyzed groups. Besides, the extension of this study to a wider selection of geopolymers, such as the pumice-, volcanic paleo-soil- and/or metakaolin-based ones, already studied with other techniques, further confirmed the efficacy of DRIFT spectroscopy in the identification of the geopolymerization reaction.

Bridging repair of the abdominal wall in a rat experimental model. Comparison between uncoated and polyethylene oxide-coated equine pericardium meshes.

Biological meshes improve the outcome of incisional hernia repairs in infected fields but often lead to recurrence after bridging techniques. Sixty male Wistar rats undergoing the excision of an abdominal wall portion and bridging mesh repair were randomised in two groups: Group A (N = 30) using the uncoated equine pericardium mesh; Group B (N = 30) using the polyethylene oxide (PEO)-coated one. No deaths were observed during treatment. Shrinkage was significantly less common in A than in B (3% vs 53%, P < 0.001). Adhesions were the most common complication and resulted significantly higher after 90 days in B than in A (90% vs 30%, P < 0.01). Microscopic examination revealed significantly (P < 0.05) higher mesh integrity, fibrosis and calcification in B compared to A. The enzymatic degradation, as assessed with Raman spectroscopy and enzyme stability test, affected A more than B. The PEO-coated equine pericardium mesh showed higher resistance to biodegradation compared to the uncoated one. Understanding the changes of these prostheses in a surgical setting may help to optimize the PEO-coating in designing new biomaterials for the bridging repair of the abdominal wall.