During the recent restoration of the Bargello courtyard and fa & ccedil;ades (13th-14th century), initiated in 2020, traces of painted polychrome decoration were identified on Pietraforte intrados and extrados of the mullioned windows. On the stone intrados, blackish lozenge-shaped impressions-likely remnants of a metallic leaf-were against a pale blue background. To investigate the original materials and painting technique, a combination of non-invasive in situ methods (digital microscopy, energy-dispersive X-ray fluorescence spectroscopy, and reflectance spectrometry) and micro-invasive analyses (optical microscope, micro-Raman, SEM-EDS, XRD, FT-IR, GC-MS, PY-GC-MS) was applied. The integrated analyses of the blue decorations revealed the presence of azurite, pseudoboleite and rare particles of lead white, along with Cu-oxalates and Ca-oxalates. The occurrence of pseudoboleite, a rare greenish mineral, suggests it formed as a result of alteration processes involving azurite and lead white, potentially triggered by chlorine-based cleaning treatments. Rare Hg-S-based particles, likely associated with vermilion, were identified in the extrados. Additionally, trace amounts of egg and a non-drying fat were detected. (c) 2025 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Tattoos have been a ubiquitous phenomenon throughout history. Now, the demand for tattoo removal for aesthetic or practical reasons is growing rapidly. This study outlines the results of field investigations into the chemical and biological removal of tattoo inks (Hexadecachlorinate copper phthalocyanine—C32Cl16CuN8—CAS no° 1328-53-6). FTIR, Py-GC/MS, and NMR analyses yielded intriguing profiles pertaining to the primary chemical constituents, along with others of an ambiguous nature. A bioremoval protocol was developed on a pork rind surface to simulate human tattooing. Two previously studied microbial strains were included in this analysis: (i) a bacterial culture of Pseudomonas stutzeri 5190 DSMZ viable cells and (ii) a fungal culture of Alternaria infectoria strain NIS4, the latter already isolated and identified. A combination of physical, chemical, and microbiological analyses, along with microscopic observations, was conducted. In our experimental conditions, inocula from environmental samples (soil and compost) were capable of inducing changes in even trace organic matter (glycerin and additives in pigments) used as a binder in emulsifiers in tattoo inks. Furthermore, the two microbial strains demonstrated promising potential for removing green tattoo ink. Finally, wastewater effluents containing green ink were recovered via electrochemical treatment, and the environmental impact in terms of the CO2 equivalent of our experiments was assessed. The results are promising and warrant further investigation into the innovative biological and chemical removal of tattoo inks from human skin and wastewater, respectively.

Ancient Ardaxšīr Khwarrah, today known as Shahr-e Gur, situated near the modern town of Firuzabad in Fars, Iran, holds historical significance as the inaugural capital city of the Sasanian Empire. During archaeological excavations conducted in 2005 by an Iranian–German team directed by Mas‘oud Azarnoush and Dietrich Huff, a mud-brick complex was uncovered, revealing a remarkably well-preserved stretch of wall painting and a polychrome painted floor. The discovery prompted the hypothesis of a potential funerary context dating back to the Sasanian period. Both the wall painting and painted floor have suffered extensive deterioration attributed to the environmental conditions of the archaeological site, which was inscribed on the UNESCO World Heritage List in 2020. To address the urgent need for preservation and further understanding of the site’s artistic and structural elements, an emergency diagnostic project was initiated. Non-invasive investigations were carried out on the wall and floor by optical digital microscopy and portable energy-dispersive X-ray fluorescence. Additionally, representative minute samples underwent analysis through various techniques, including micro-X-ray fluorescence, polarised light microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, micro-Raman spectroscopy, micro-Fourier Transform Infrared Spectroscopy, gas chromatography-mass spectrometry and pyrolysis coupled with gas chromatography-mass spectrometry. The palette of the floor and mural paintings were identified to contain red and yellow ochres, lead-based pigments, carbon black and bone white. The unexpected presence of Egyptian blue mixed with green earth was recognised in the green hues of the wall painting. The detection of protein material in both the wall painting and polychrome floor indicates the use of “a secco” technique, thereby shedding light on the artistic practices employed in Ardaxšīr Khwarrah.

This paper describes the application of the Er:YAG laser for the cleaning of a 17th-century polychrome wood sculpture which was originally opulently gilded, but had been totally overpainted around the nineteenth century. A series of diagnostic analyses and laser tests have been performed for a comprehensive understanding of the artistic-technique and the state of preservation, and for controlling the laser cleaning. Cross-sections of minute fragments and samples collected by the Er:YAG laser allowed us to understand the complex stratigraphy. PY-GC-MS, SEM-EDX, and XRF analyses highlighted the challenge of this cleaning work. It has been considered appropriate to remove gradually the overpaints on the clothing of the Virgin in order to uncover the original gilded portion, although it might be extremely degraded. The Er:YAG laser ablation allowed the selective removal of different layers of multi-colored overpaint and of the thick and resistant past restoration infilling which covered the thin degraded original layers.

The stone surfaces of the inner east side of Cemetery of Pisa are affected by extensive deterioration phenomena connected with the lithotype and the environmental condition. Past consolidating and protective treatments have improved the flaking and powdering of the stone, which made impossible to use traditional cleaning methods. For the gradual removal of soil and altered film, the single or combined action of two mid-infrared lasers operating at different wavelength were tested: Nd:YAG laser (1064 nm, 6 ns) and Er:YAG laser (2940 nm, 150 mu s, 250 mu s, 400 mu s). The optimal cleaning parameters have been settled up varying the fluence, pulse duration, and wetting conditions for each typology of material to be removed. Test evaluations have been carried out by comparing the marble surface before and after the laser treatment with different analytical techniques. The optimized laser cleaning methodology has been successfully applied for the complete and safe cleaning of the pillar and its carved capital.

This article describes a multi-analytical technical study of a rare painted shroud still wrapped around a female Egyptian mummy (MCABo EG 1974) in the collection of the Museo Civico Archeologico of Bologna, Italy. Long stored in the museum's warehouses, these mummified human remains were recently rediscovered within the Bologna Mummy Project (BOmp), an interdisciplinary endeavor promoted by the Museo Civico Archeologico and the Institute for Mummy Studies of Eurac Research, Bolzano, Italy. Dating to the Roman period (1st-2nd century C.E.), as confirmed by radiocarbon dating, this mummy displays a unique series of technical features, including the exceptional finding of a colorful painted shroud still preserved in its original location around the wrapped body, to which it is secured with textile straps and resin. In this context, scientific analysis aimed to deepen our current knowledge of the artistic practices of Roman Egypt through an in-depth study of the painting technique, context of production, and possible provenance of the mummy, while promoting a science-informed, enhanced approach to the preservation of the mummified human remains. This research relied on an integrated analytical protocol based on the combined use of imaging and mapping techniques, non-invasive point analysis, and micro-invasive investigation of minute samples, each carried out at the different partnering institutions. Computed tomography (CT) highlighted varying radio-densities for some of the flesh tones and red decorations. Visible photography and multiband imaging provided information on the nature and distribution of various materials on the surface. Fiber optics reflectance spectroscopy (FORS), X-ray fluorescence (XRF) spectroscopy, and Raman spectroscopy contributed to the characterization of the shroud's color palette along with optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), as well as high-performance liquid chromatography coupled with diode-array detection and mass spectrometry (HPLC/DAD and HPLC/MS). Materials detected include a limited number of mineral pigments and plant-derived dyes such as red lead, red ocher, madder, an unknown yellow dye, Egyptian blue and green, and a carbon-based black. Through access to MOLAB equipment and expertise, macroXRF (MA-XRF), as well as combined X-ray diffraction (XRD) spot analysis and mapping, enhanced pigment identification. A combination of transmission Fourier-transform infrared (FTIR) spectroscopy with gas chromatography / mass spectrometry (GC/MS) was used to identify the paint binders and any addi- tional organic substances possibly involved in embalming practices and ritual traditions, including animal fat, plant lipid, Pinaceae resin, gum, and beeswax. Mineralogical data gathered by XRD on surface deposits and soil residues collected from within the shroud's inner folds was crucial to put forward hypotheses, in support of the stylistic study of the shroud, concerning a possible provenance from Upper Egypt, most likely West Thebes. Both the shroud and inner bandages were found to be made with linen using OM. After undergoing scientific analysis and conservation treatment, the mummy was displayed in the "Mum- mies. Unwrapping the past" exhibition and was featured at the 10th World Congress on Mummy Studies, both held in Bolzano in the fall of 2022. (c) 2024 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

In the context of the archaeometrical study of Saturnino Gatti’s wall paintings, a significant aspect concerned the study of the organic component to understand both the original binders used in the original areas and the products used for pictorial reintegration and restoration of the painted surfaces. Thanks to the results obtained from various non-invasive and multi-band imaging techniques, it was possible to define Gatti’s original painting technique and identify the materials subsequently applied in significant samples. To this end, molecular analyses based on mass spectrometry were carried out. Different procedures in gas chromatography–mass spectrometry (GC-MS) and in pyrolysis coupled with gas chromatography–mass spectrometry (Py-GC-MS) were adopted. The analyses revealed a variety of organic materials on the mural paintings, most of which are from past restoration interventions and have synthetic origin. The overspread presence of paraffin is likely due to the application of a mineral wax-based coating/consolidant. In particular, the execution technique encompassed the use of tempera-based paints, while retouched areas were characterised by the presence of oil-based resins.

Although ceramic objects are an important part of the worldwide cultural heritage, few investigations on the effects of lithobiontic growth on their outdoor conservation are available in the literature. Many aspects of the interaction between lithobionts and stones are still unknown or strongly debated, as in the case of equilibria between biodeterioration and bioprotection. This paper describes research on the colonization by lithobionts on outdoor ceramic Roman dolia and contemporary sculptures of the International Museum of Ceramics, Faenza (Italy). Accordingly, the study i) characterized the mineralogical composition and petrographic structure of the artworks, ii) performed porosimetric measurements, iii) identified lichen and microbial diversity, iv) elucidated the interaction of the lithobionts with the substrates. Moreover, v) the measurements of variability in stone surface hardness and in water absorption of colonized and uncolonized areas were collected to assess damaging and/or protective effects by the lithobionts. The investigation showed how the biological colonization depends on physical properties of the substrates as well on climatic conditions of environments in which the ceramic artworks are located. The results indicated that lichens Protoparmeliopsis muralis and Lecanora campestris may have a bioprotective effect on ceramics with high total porosity and pores with very small diameters, as they poorly penetrate the substrate, do not negatively affect surface hardness and are able to reduce the amount of absorbed water limiting the water ingress. By contrast, Verrucaria nigrescens, here widely found in association with rock-dwelling fungi, deeply penetrate terracotta causing substrate disaggregation, with negative consequences on surface hardness and water absorption. Accordingly, a careful evaluation of the negative and positive effects of lichens must be carried out before deciding their removal. Regarding biofilms, their barrier efficacy is related to their thickness and composition. Even if thin, they can impact negatively on substrates enhancing the water absorption in comparison to uncolonized parts.

Background Nipple adenoma is a very uncommon, benign neoplasm that involves the nipple. A palpable mass of the nipple associated with nipple discharge and erosion or ulceration is the common clinical presentation. Generally, complete surgical excision of the nipple is the main treatment, alternative therapeutic methods such as Mohs micrographic surgery, nipple splitting enucleation, and cryotherapy can be considered. Disorders of the breast in young women are generally benign. Even if the management during pregnancy is usually conservative and surgical excision is reserved for very strong malignancy suspicion, benign lesions can cause the impossibility to breastfeed after giving birth when involving the nipple. Case presentation We present the case of a 28-year-old female, who was referred to the Breast Unit of the University Hospital of Modena (Italy) in May 2020 with a 12-months history of enlargement of the left nipple with associated erythema, serohemorrhagic discharge, and pain in the left nipple region. The diagnostic assessment came out in favor of a nipple adenoma. After surgical treatment was recommended, the patient got pregnant. Taking into account the major risks of surgery during pregnancy, a multidisciplinary discussion was conducted, to consider whether to proceed with surgery or postpone it after pregnancy. Because of the volume and the position of the adenoma, the indication for surgical excision was confirmed, to allow regular lactation and breastfeeding immediately after giving birth and to avoid potential obstructive complications. Surgical excision of nipple adenoma without complete resection of the nipple was performed after her first trimester of pregnancy under local anesthesia. A histopathological examination confirmed the diagnosis. No recurrence occurred after 12 months. The patient gave birth, had no deficit in lactation, and successfully breastfed. Conclusions Therefore, we consider that nipple adenoma enucleation might be a safe treatment even during pregnancy. Moreover, conservative local treatment of nipple adenomas can preserve the nipple aesthetically and functionally, thus allowing regular lactation and breastfeeding in young women.

The study of ancient architectural restoration has recently gained attention in the field of archaeometry thanks to a new sensitivity for the long biographies of human artifacts. The paper focuses on ancient repairs documented in the column shafts of the Monumental Nymphaeum of Tripolis ad Maeandrum (Denizli, Turkey). Bonding mortars used to hold the ancient patches in place were sampled and analysed according to a multi-analytical protocol, coupling mineralogical and petrographic investigation (XRPD and OM) together with FT-IR and chromatographic and mass spectrometric techniques (i.e. Py–GC–MS, GC–MS, HPLC-MS) for the characterisation of the inorganic and organic components. For the inorganic part, medium and fine-grained crystals of calcite are used as aggregates. As for the organic fractions, three different ingredients have been detected: egg, beeswax and Pinaceae resin. These multi-ingredient recipes detected in Tripolis are discussed with reference to ancient literary sources and the results of scientific investigations previously performed on ancient architectural repairs in the nearby city of Hierapolis of Phrygia, to highlight functional and chronological differences.

Defendente Ferrari, one of the most important painters of the Piedmontese Renaissance, was extremely active in the early 16th century. His Madonna with Child and two Saints (1505-1510 ca.), which was originally located in the Collegiate Church of Carmagnola (Turin province, Italy) now in the collections of Palazzo Madama -Museo Civico d'Arte Antica in Turin, was recently analyzed and restored at the Centro Conservazione e Restauro La Venaria Reale, as part of a study and conservation project focused on the artist and his circle. This study presents an interdisciplinary and multi-analytical archaeometric approach resulting from the collaboration of several universities and research centers. The adopted protocol allowed for clarifying some peculiarities of the artist's painting technique, such as the use of the dotted -a technique applied to render the nuances, volume, and flesh tones of the figures -and that of thin black cross-hatched strokes, drawn to shape the clothes and to define the related volumes and folds. Moreover, specific degradation processes were studied, which apparently occur also in other contemporary artworks with similar features. Of particular interest is the alteration of the blue color of the Virgin's garment, made of azurite and presently strongly blackened. SWIR reflectography performed with a high-resolution InGaAs scanner prototype allowed for imaging both the detailed underdrawing and the careful hatching used to highlight the shadows. The combined application of optical microscopy, SEM-EDS, mu-Raman, FT-IR spectroscopy, and GC-MS has been fundamental for analyzing some specific pigments, binders, and varnishes, as well as for inferring the cause for Virgin's garment blackening. A complete mapping of the pigments was provided through the combination of FORS (350-2000 nm), portable mu-Raman, MA-XRF, and Hypercolorimetric Multispectral Imaging. The latter also allowed for observing the distribution of what is supposed to be either the original or the ancient organic finishing layer, which was maintained during the conservation treatment. This research has brought to an in-depth knowledge of the artist's painting technique and helped the adoption of the best choices for an effective and minimal-invasive restoration intervention.

Abstract Background: Nipple Adenoma is a very uncommon, benign neoplasm that involves the nipple. Generally, complete surgical excision of the nipple is the main treatment, alternative therapeutic methods such as Mohs micrographic surgery, nipple splitting enucleation, and cryotherapy can be considered. Benign disorders of the breast generally occur in the breast of young women. Even if the management during pregnancy is usually conservative and surgical excision is reserved for very strong malignancy suspicion, benign lesions can cause the impossibility to breastfeed after giving birth when involving the nipple. Case Presentation: Here, we report a case of a 28-year-old woman with a 12-month history of progressive enlargement of the left nipple associated with erythema and intermittent serous-haematic discharge. The diagnostic assessment came out in favor of a nipple adenoma. After surgical treatment was recommended, the patient got pregnant. Surgical excision of nipple adenoma without complete resection of the nipple was performed after her first trimester of pregnancy under local anesthesia. A histopathological examination confirmed the diagnosis. No recurrence occurred after 12 months. The patient gave birth, had no deficit in lactation, and successfully breastfed. Conclusions: Therefore, we consider that nipple adenoma enucleation might be a safe treatment even during pregnancy. Moreover, conservative local treatment of nipple adenomas can preserve the nipple aesthetically and functionally, thus allowing regular lactation and breastfeeding in young women.

After the cleaning procedures carried out during a recent restoration work, the Matera Cathedral's (UNESCO World Heritage Site) facade needed the application of a water repellent treatment. Aqueous emulsions of silanes/siloxanes, also in a mixture with acrylic polymer and an alkyl/alkoxysilanic resin (by BEL CHIMICA S.r.l. and PHASE restauro S.r.l), have been tested as representative of the most used formulations in the restoration of buildings in Italy, especially in the last decade. This paper focuses on the best practices to be adopted for the identification of the suitable protective product in terms of effectiveness, harmfulness and durability, in particular respect to photo-aging and thermo-hygrometrical aging. The conservation materials have been testedin situand in laboratory on a stone block expressly extracted from the monument. The chemical composition of the products and their degradation processes were characterized by means of FT-IR and PY-GC-MS. The performance of the treatments was evaluated, both in laboratory by permeability, color and capillarity measurements and in situ by non-destructive techniques (IR reflectance spectroscopy, color measurements, water absorption tests by contact sponge). Silane/siloxane emulsion presented more pronounced degradation phenomena after artificial aging, while the mixture of silanes/siloxanes and acrylic polymers decreased the permeability to water vapour.

Gandharan art developed in the Himalayan area in the early centuries CE. It has been investigated mostly from an iconographic point of view, missing, until very recently, a systematic technical investigation of materials and techniques. Recently our team began performing chemical analyses of the traces of the polychromy originally covering statues, reliefs and architectural decorations, to discover the ancient painting techniques and artistic technologies. This paper presents the results of the analytical investigation (optical microscopy, Raman spectroscopy and gas chromatography coupled with mass spectrometry) of pigments, ground layers and binders of a new group of samples taken from stucco architectural decorations (2nd–3rd/4th centuries CE). The samples were collected directly at an archaeological site in the Swat Valley, ensuring the exact knowledge of their stratigraphic provenance, as well as the absence of any restoration treatment applied prior sampling. The results are discussed in the wider context of Gandharan polychromy investigated so far by our team, as found in sculptures and architectural decorations preserved in museums (in Italy and France) and in archaeological excavations in Pakistan. The aim of this research is to shed light on the materials and techniques of this Buddhist ancient art from this region and on the influences exerted on it from Eastern and Western artistic traditions.

The chemical analysis of organic paint material is still one of our most important tools for understanding an object, planning its conservation, and supporting speculations on the object's identity and history. Analytical pyrolysis is a micro-destructive analytical technique that chemically characterizes organic materials in a large range of molecular weights, directly in the solid state, without the need for any pretreatment. This makes the technique particularly useful when dealing with samples from a work of art and archaeological object, where typically the composition in terms of significant analytes and the matrix is not known before the analysis, and natural and synthetic materials may be expected simultaneously. In this chapter the use of analytical pyrolysis for the molecular characterisation of organic materials in case studies from archaeological objects and works of art, spanning from the fourth century BC to the 1980s, is presented. The aim is to discuss how analytical pyrolysis can contribute to issues related to the identification of artistic techniques, to reconstruct the history of an object through the study of its chemical signature, and to differentiate between original and non-original materials in paintings.

Ewing's Sarcoma Family Tumors (ESFT) include classic Ewing's sarcoma of bone, extra-skeletal Ewing's sarcoma (EES), malignant small cell tumor of the chest wall (Askin tumor), and soft tissue-based Peripheral Primitive Neuroectodermal tumors (pPNET). The t(11;22)(q24;q12) translocation is associated with 85% of tumors and leads to EWS-FLI-1 (Ewing's Sarcoma-Friend Leukemia Integration-1) formation. This is a potent transforming gene that encodes a chimeric protein that plays a role in the genesis of Ewing's Sarcoma and Primitive Neuroectodermal Tumors. The breast location of ESFT remains exceptional. The prognosis is among the poorest of all subtypes of breast cancer and even poorer than other extraosseous Ewing's sarcomas. We describe the case report of a 23-year-old patient with a growing breast lump, who required an accurate and challenging diagnostic estimation and who ultimately resulted in a peripheral primary neuroectodermal tumor (pPNET). Through this case description and a brief narrative review of the literature, we aim to highlight the rarity of ESFT located in the breast. Histopathological confirmation is mandatory for all growing masses of the breast to reach a conclusive diagnosis and plan the correct treatment. Patients with rare diagnoses should always be centralized in breast units, conducting multidisciplinary meetings and, when necessary, the diagnosis should be shared through wider national or international registries.

This study is part of a comprehensive investigation that was performed in regard to a case of alterations on a carbographic ribbon used in a typewriter that was found and seized by inner security operations of the Arma dei Carabinieri, Italy. Thirty‐six coded scripts possessing potentially and criminally liable content were present on the tape; however, only the 6th and 7th scripts exhibited alterations of an uncertain nature. The study included sampling that was performed under sterile conditions of a large surface area of carbographic ribbons. A protocol based on physico‐chemical, microbiological, and biomolecular tools was established. Preliminary results revealed the presence of fungal contamination that was primarily located on the inner surface of the 6th and 7th scripts on the black carbographic ribbon. One fungal strain was isolated and identified by universal ITS‐PCR primer and rDNA sequencing as Alternaria infectoria strain NIS4. Fungal growth was monitored for 3 weeks in the laboratory under different environmental conditions (temperature, open‐closed system, and substrate). The A. infectoria NIS4 strain exhibited the best growth at 28°C under a closed system with RH near saturation. We also noted that the fungal growth was abundant at 15°C. Moreover, this fungus (a potential human pathogen) possessed the ability to colonize the surface of the new carbographic ribbon even when using mineral medium; however, this only occurred in a closed system environment and not in open systems due to rapid desiccation. Under our experimental conditions, the A. infectoria NIS4 strain could degrade gelatin as an organic matter present in trace amounts that are often used as a binder in a carbographic ribbon emulsions. The results revealed that the isolated microorganism was the major biological candidate capable of altering the investigated carbographic ribbon; however, these alterations could only occur under favourable environmental conditions.

INTRODUCTIONSpider bites are common worldwide. Frequently symptoms resolve without any adverse outcome, but in rare cases the bite can cause severe morbidity. The most typical presentation of Mediterranean recluse spider (Loxosceles Rufescens) bite is a dermatonecrotic lesion of the skin (skin loxoscelism). When the only manifestation of a spider bite is an ulcerated skin lesion, clinical suspicion and differential diagnosis strongly depend on its site. We present the case of an ulcerated wound of the breast, diagnosed as a Mediterranean recluse spider bite.CASE PRESENTATIONA 79-year-old woman presented a 10cm-wide soft tissue ulceration of her left breast. At first, the diagnostic hypothesis of an ulcerated cancer was ruled out. Two family members revealed a recent history of Mediterranean recluse spider bite and the same clinical diagnosis was made for our patient. A wide excision was performed, with complete resolution of symptoms.DISCUSSIONNo specific diagnostic criteria for spider bites are available. Diagnosis is usually clinical. Skin loxoscelism could be easily mistaken for cellulitis, various types of skin infections, cutaneous anthrax, vasculitis, scorpion sting, pyoderma gangrenosum, erythema migrans of Lyme disease or prurigo nodularis. A thorough anamnestic interview is fundamental to raise the diagnostic hypothesis. When possible, a biopsy is recommended and it is extremely important when the ulcer can mimic a cancer, as is the case in breast tissue.CONCLUSIONWe recommend a wide excision of the wound after failure of conservative treatment, in order to obtain local control and to perform histological examination on a more representative specimen.

This study integrates the complex research conducted on the sources of brown discolorations that occur on marble statues (fifteenth century) of the Church of Orsanmichele in Florence (Italy). They underwent conservative interventions in the past and the brownish discolorations on their surfaces strongly altered the clear tone of the marble. In this study, Carrara marble model specimens were treated with organic and inorganic substances (non-pasteurised milk; linseed oil; walnut oil; ammonium oxalate; microcrystalline wax; beeswax; milk + linseed oil; and milk + ammonium oxalate + linseed oil) to simulate their effects on the stone. Some of the substances were commonly used in the past (as on the Orsanmichele statues) but most of them are still used in many countries. The treated specimens were exposed to natural and artificial ageing. The main results of the research were (i) the specimens treated with linseed oil, milk + linseed oil, and milk + linseed oil + ammonium oxalate showed a severe change of colour after either artificial or natural ageing; (ii) an extensive polymerisation of the organic substances occurred; (iii) calcium oxalate and several oxidised diacylglycerols (DAGs) and triacylglycerols (TAGs) were the last chemical products of the oxidation processes induced by ageing; (iv) Maillard reaction, producing brownish coloration, likely occurred in specimens containing milk as a result of the interaction between sugars and proteins.