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The greenstone industry of Valgrana/Tetto Chiappello was studied with an archaeo-typological and mineral/petrographic approach (functional study, XRPD, polarized light microscopy and SEM-EDS), to infer the provenance of the raw materials and the role of this site in the general greenstone circulation during Neolithic. Most artifacts (mainly cutting-edge tools) are made of sensu stricto greenstones (≈ 80%), especially mixed Na-pyroxenite and eclogite in roughly equal amounts. The abundance of roughouts and broken tools, with evident use-wear traces, suggests that these implements were possibly used even before (or sometimes without) pre-shaping. Based on mineralogical and morphological ‘markers’, a dual mechanism of raw materials supplying was hypothesized for Valgrana: most tools were retrieved from the closer areas of the southern Monviso ‘massif’ (few dozens of km far, as the crow flies), though a subordinate supply channel was probably represented by commercial trades with other settlements, thus allowing the stocking of raw materials and/or artifacts also from the more distant Voltri ‘massif’ (70-to-80 km far). For what concerns the provisioning mode, a ‘secondary high-ground supplying’ mainly operated in Valgrana, according to which the raw materials were retrieved from greenstone boulders dismantled by erosion and rolled down along the Monviso ‘massif’ mountainsides; however, it cannot be excluded that direct extraction from primary outcrops may also have occurred. In the operative chain, Valgrana can be identified as a subordinate sedentary ‘satellite site’, in which specialized workers took care of raw materials gathering and preliminary tool processing – to be continued and concluded elsewhere.

This study provides the first characterization of Fe-rich antigorite (FeOtot up to 12 wt%), a rock-forming mineral occurring in ophicarbonate rocks from different low-temperature/high-pressure meta-ophiolitic suites: Acceglio (Traversiera Valley, external Piemonte Zone, NW Italy), Macedonia and Verias (Thessaloniki and Vurinos-Kozani ophiolitic complexes, NE Greece), Tinos (Tinos Island, Cyclades Archipelago, Greece). Fe-rich antigorite has been characterized through optical and transmission electron microscopy (TEM), and its mineral chemistry has been investigated by means of wavelength-dispersive and TEM-based energy dispersive spectrometry. In thin section, Fe-rich antigorite is characterized by a strong, peculiar pleochroism (alfa = green-dark green; gamma = bright-yellow-orange). It occurs in both mesh and bastite microstructures, and it is locally associated with relics of lizardite and/ or chrysotile. The modulated lattice parameters of disordered Fe-rich antigorites have been determined by electron diffraction in the transmission electron microscope. The values are highly variable, even within each ophicarbonate sample. Verias dominantly has a superlattice parameter a clustering around 43.5 Å (corresponding to the m = 17 polysome); Tinos and Macedonia have around 35.4 Å (m = 14); Acceglio may even go down to 29 Å (m = 12). Globally, the disorder features (i.e., reduced size of crystals, polysomatic faults, wobbling, misalignment among sublattice and superlattice reflections, etc.) increase from Macedonia to Verias, Tinos and Acceglio, respectively. The analyzed Fe-rich antigorites accommodate up to 12 wt% FeOtot, with XFe values (XFe = Fetot/[Mg + Fetot]) in the range 0.10-0.16 for Macedonia, 0.05-0.17 for Acceglio, 0.10-0.12 for Tinos and 0.05-0.10 for Verias. The intensity of the pleochroism seems to be directly correlated with the Fe content, with the Fe-richer samples showing the deeper absorption colours. Mineral relationships and TEM observations suggest that Fe-rich antigorite replaces former mesh and bastite microstructures consisting of lizardite ± chrysotile, only locally preserved as relict phases. The thermodynamic modelling approach (i.e., P/T-X(CO2) pseudosection) qualitatively shows that the stability of Fe-rich antigorite is compatible with low-temperature, high-pressure conditions (i.e., blueschist-facies metamorphic conditions), and is enhanced by the occurrence of CO2 in the fluid, consistent with the systematic occurrence of this mineral in meta-ophicarbonate rocks.

In order to promote geosite conservation in the project entitled 'PROactive management of GEOlogical heritage in the PIEMONTE Region', we propose a comprehensive study involving the Monviso Massif (MM) geothematic area, one of the most outstanding symbols of the Alps and particularly of the Cottian Alps. Specifically, at the MM, the inventory of a number of different geosites whose conservation and development require different geologic and some additional non-geological expertise is considered: (1) some of the best preserved ophiolites in the Alps and the associated Cu-Fe mineralizations; (2) the lithostructural units in the Germanasca Valley; (3) the first primary source of jade in the Alps at the MM and its importance in terms of Neolithic to Bronze Age-polished stone implements; (4) the world-famous minerals such as coesite and giant pyrope, as well as type localities for new minerals (including carlosturanite); (5) the area, now buried under a debris flow, where Hannibal is thought to have regrouped his army while crossing the Alps; and (6) the biodiversity of lichens, microfungi and cyanobacteria colonizing the ophiolites, which can give additional value for the environmental assessment and evaluation of the MM outcrops. Following geodiversity identification, further stages will be devoted to develop appropriate plans for geodiversity conservation in this area.

In many urban and natural areas, the presence of naturally occurring asbestos (NOA) requires a geological risk evaluation to enforce safety and exposure monitoring during the achievement of surface and subsurface infrastructures. A set up of proper procedures must provide: (i) a detailed geological model of the possible presence of the asbestos, (ii) a representative sampling, (iii) a correct analytical approach, and (iv) a working procedure that can be efficiently applied during excavation activities. At present, the EU regulations for a safety work in asbestos-bearing materials are still not exhaustive because of the great complexity of the matter and uncertainties in geological risk definition. This paper presents two case studies where the different involved parties (scientific community, environmental agencies, and private companies) jointly contributed to find technical solutions for a correct risk management of excavations in asbestos-bearing rocks as well as reliable analytical procedures for quantitative determination of the fibre content.

The Monviso Ophiolite (MO) in the Italian Western Alps is one of the best known relics of oceanic crust in the orogen. Moreover, it is one of the strategic areas chosen to represent the geodiversity of Piemonte Region (Rolfo et al. 2014). The MO gives the chance to see and appreciate different portions of the ancient ocean along a relatively short mountain trail; from the Po river springs at Pian del Re, a path from 2000 m up to about 2350 m a.s.l. shows all different ophiolitic lithologies - modified after the Alpine evolution - within few kilometers.

A block is described, which is exposed in the antigorite serpentinite of Vallone Bulè, belonging to the Basal Serpentinite Unit of the Monviso massif (Piemonte Zone of calcschists with meta-ophiolites). The block consists of a quartz-jadeite rock core and a jadeitite rim, very similar to the rocks used by prehistoric men to make stone axeheads. In spite of their different bulk-rock compositions, both core and rim show the same trace and rare earth elements patterns, suggesting the same protolith. The quartz-jadeite rock exhibits a major, trace and rare earth elements composition consistent with that of oceanic plagiogranite, most likely a dyke cutting across upper mantle peridotites, later hydrated to serpentinites. Conversely, the jadeitite, which consists mainly of zoned jadeite crystals progressively enriched in the diopside component from core to rim, is significantly depleted in Si but enriched in Mg and Ca with respect to the quartz-jadeite rock. The trace and rare earth elements similarities and the ubiquitous presence of small zircons suggest that the jadeitite and the quartz-jadeite rock both derive from a plagiogranite; however, jadeitite would have undergone a metasomatic process involving a significant desilication and Mg- and Ca-enrichment, connected to the host peridotite serpentinization. The process, responsible for the transformation of the plagiogranite into a jadeitite, should have occurred during prograde Alpine high-pressure (eclogite-facies) metamorphism, since the first Na-pyroxene formed is jadeite, corroded and partly replaced during the metasomatic process by a progressively more omphacitic pyroxene. Because similar rocks - mostly jadeitites, but even their plagiogranite protoliths - are reported from other localities from the Western and Maritime Alps, it is likely that the raw materials of most jadeitites used to make stone axeheads, which are spread all over the Western Europe, have a similar origin and derive from the western Alps as long suggested.

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