Editorial for Special Issue “Geomaterials and Cultural Heritage”

The Special Issue entitled “Geomaterials and Cultural Heritage” serves as a platform to gather contributions at the intersection between Heritage Science, Earth Sciences, Materials Science, and Museum Studies. Eight research papers were collected, representing the wide variety of themes, research questions, and methodologies that can be developed through an interdisciplinary approach.

Burgio (Contribution 1) illustrates the discovery of the use of bismuth oxychloride as a white pigment in portrait miniatures by George Engleheart (1752–1829) at the Victoria and Albert Museum in London, UK; the paper reviews previous studies on bismuth-based artists’ pigments and paves the way for new, systematic studies on the subject.

The paper by Doménech-Carbó et al. (Contribution 2) presents an uncommon application of geosciences to underwater archaeology, focusing on the geochemical study of the burial context of the Phoenician shipwreck ”Mazarròn 2”, one of the most ancient found in the Mediterranean Sea (7th–6th century BCE); the research helped in assessing the condition of the shipwreck, guide its future conservation, and evaluate the possible impact of the shipwreck metal cargo in modifying the local environment.

The study of a museum object is the focus of the paper by Iannaccone et al. (Contribution 3). The authors characterised the geomaterials (lithic support, mortars, and pigments) of a Roman cippus dating to the 1st century BCE and found in Sardinia, Italy, providing information of archaeological and conservative relevance.

Calandra et al. (Contribution 4) applied a multi-technique approach to study the composition and degradation of the decorative plasters of a 19th-century chapel in Florence, Italy. The characterisation of the materials was coupled with the 3D digital reconstruction of the chapel, including a degradation map, with the aim of supporting and guiding the conservation and restoration interventions.

The novel application of synchrotron-radiation micro-X-ray diffraction in transmission geometry (SR-μTXRD) to the study of multi-layer paints was tested on mock-up samples by Morabito et al. (Contribution 5). SR-μTXRD linear mapping facilitated the reconstruction of the microstructure of these complex samples, and the identification and quantification of the crystalline phases (pigments and fillers) with different grain size and spatial orientation, suggesting promising applications on real cultural heritage painted surfaces.

Ethnoarchaeology, archaeometry, and material sciences are at the base of the paper by Pérez et al. (Contribution 6), who analysed pottery manufactured by contemporary artisans following the traditional recipes of the Yucatán Peninsula, México. The study facilitated the characterisation of the ceramic and local raw materials, thus providing information on the traditional know-how, and to test a multi-analytical protocol to be applied also to archaeological objects from the same region.

Finally, Natural History Museums and their mineralogical collections are at the centre of the papers by Apopei et al. (Contribution 7) and Fabrizi et al. (Contribution 8).

Apopei et al. constructed an online, open-access repository featuring 3D digital models of a wide selection of rocks and minerals from the “Grigore Cobălcescu” Museum of the University of Iaşi in Romania. It serves as a valuable tool for scientific research, education, and public outreach, with the aim of enhancing the impact of geosciences museums within the context of the ongoing digital transformation. The paper also provides a comprehensive review of studies on digital technologies and platforms, and geo-mineralogical collections.

The contribution by Fabrizi et al. concerns the study of a significant historical gemstones collection, which forms one of the earliest cores of the Natural History Museum of the University of Florence, Italy, possibly dating back to the 15th century. The identification of the mineral species and, in some cases, the geographical provenance of the gems were determined using a completely non-invasive approach, which combined Raman microscopy and Ion Beam Analysis. These scientific results were integrated with archival and historical research, contributing to a better interpretation and enhancement of the studied collection and its history.

In conclusion, this Special Issue emphasises the multiple interconnections between geosciences and cultural heritage studies, demonstrating how these synergies can enhance the understanding, conservation, and valorisation of archaeological, artistic, and natural heritage.