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The stone used on the monuments, especially if they come from ancient times (e.g. medieval period), when exposed to the atmosphere, they are frequently affected by weathering and bio-deterioration processes. Thus, these latter produce various chemical and mineralogical transformations of substrate at the interface with the atmospheric agents as function of intrinsic compositional and physical characteristics of the material. Moreover, if there also are ancient treatments on the surface of geomaterials, the investigation field is further complicated. This research aims to analyse the surfaces of different volcanic lithology (basalts, andesite, pyroclastic rocks) used in the medieval Romanesque churches of Sardinia (XI-XIV cent.) having high historical-architectural and cultural relevance. By mineralogical and petrographic analysis (OM) and other different analytical methods (XRPD, colorimetry) the investigations addressed to define: i) petrographic features of volcanic rocks substrate; ii) chemical and mineralogical composition of coatings/crusts and any salt fanoand cryptoefflorescence; iii) compositional and microstratigraphic characterization of ancient treatments (i.e., Ca-oxalate films) on the surface of facades; iv) chromatic modifications of surface with respect to the substrate due to the alteration processes. The results show the incidence of several factors in the alteration process, as function of the occurred time, petrophysical features and composition of geomaterials, their position in the monument structure, exposition to the weathering processes, microclimatic characteristics, environmental conditions.

Nell’ambito di un ampio progetto di ricerca sui materiali impiegati nell’edilizia del centro storico di Siena (Italia) è stato intrapreso uno studio mineralogico-petrografico sulle malte di allettamento provenienti dalle fortificazioni progettate da Baldassarre Peruzzi nella prima metà del XVI secolo e un confronto con malte impiegate in settori della cerchia muraria risalenti ad epoche precedenti (XIV e XV secolo). Le indagini preliminari hanno consentito di verificare l’impiego di malte di diversa tipología nelle fortificazioni peruzziane rispetto a quelle antecedenti, con uso di calci ad elevato indice di idraulicità e maggiore cura nella selezione e nel trattamento degli aggregati. Queste evidenze suggeriscono una scelta deliberata di nuovi materiali, più avanzati sul piano tecnologico, nel contesto di importanti interventi di potenziamento delle difese cittadine attuati agli inizi del Cinquecento.

In 1971, a complete burial of an adolescent male (Paglicci II) was found in the Evolved Gravettian layers at Grotta Paglicci (Rignano Garganico, Foggia, Southern Italy). Nearly 20 years after (1988–1989), the burial of a young woman belonging to the same cultural complex (Paglicci III) was brought to light. The re-examination of ochre and grave goods/parures from both burials provided new insights about the ritual behaviour and the technological know-how in raw material processing of the Gravettian groups. Analyses were carried out by means of 3D optical microscopy, polarized light microscopy in thin section, XRD, ICP-OES, SEM, TEM, HPLC and ToF-SIMS. Investigation was performed on a fragment of manganese oxides bearing deep incisions (discovered between the ankles of Paglicci II), which is nearly unique in the Upper Palaeolithic funerary contexts. Use-wear observations on this block suggested that it was used to obtain black pigment with different kinds of actions. Ochre materials were analysed in order to identify their nature and their processing techniques. This study was integrated with the study of a sample of natural local reddish soil and with experimental analyses carried out by grinding coarse hematites under various operative conditions. Results detected the characteristics of raw materials: a nanosized hematite-rich clayey natural material, likely technologically ready for use (Paglicci III ochre), and a mixture of a clayey–silty sand with a natural earthy-micaceous hematite (Paglicci II ochre). New inferences from the behavioural standpoint (such as the use/non-use of the grave goods, the connection between the parure shells and the sex of the dead and the hairstyling of the woman) as well as a range of possible raw material procurement sources are discussed.