Pietro Marescotti

... Alberto Martinelli*, I, Maurizio FerrettiII, Riccardo BassoIII, Roberto CabellaIII, Gabriella LucchettiIII, Pietro MarescottiIII and Vincenzo BuscagliaIV ... time 10s) using the crystallographic data for (FeSb)O4 and TiO2 reported by Amador and Rasines [13], and by Shintani et al. ...

ABSTRACT Soil colour is mainly infl uenced by the presence of colour-bearing minerals. In sulphides mine dumps (similar to natural soils but without signifi cant organic and biological components), the main colouring agents are represented by several Fe-oxides, -oxyhydroxides and -oxyhydroxysulfates that form as a consequence of the AMD (Acid Mine Drainage) processes. In this work, after a review on the state of art, we present a case study about the relationships between colour and mineralogical composition from a sulphide-bearing waste-rock dump of the Libiola mine (Eastern Liguria, Italy). The dump is highly heterogeneous in granulometry, lithology, mineralogy and chemistry, either laterally or in vertical sections. Mineralogical analyses (optical microscopy, SEM-EDS, XRPD), associated with colour data (Munsell and CIE-L*a*b* colour parameters) confi rm the correlation of the yellow hue/+b* (yellow) with the diffuse presence of goethite and the correlation of the red hue/+a* (red) with the presence of hematite. The results suggest that the characterization of the colour of waste-rock samples is a valuable and quick method to evaluate the presence and the distribution of the secondary products of AMD within highly heterogeneous mine waste disposals. Moreover, the results can be used as a quick indicator to plan field works and to design a sampling campaign.

Abstract: Recently, several techniques based on synchrotron radiation have been applied to environmental sciences giving the possibility for non-destructive investigations with micrometer spatial resolution. In particular, a combination of synchrotron methods (μ-XRF, ...

ABSTRACT The relationships between minerals and contaminants are an important topic of Environmental Mineralogy and Geochemistry. A multi-scale, multidisciplinary analytical approach is peculiar to both field- and laboratory-oriented studies conducted by means of the combined use of traditional and advanced analytical techniques available either in conventional laboratories or in synchrotron analytical facilities. An important objective in this type of studies is to develop models capable to relate molecular- and micro-scale data to macroscopic observations, i.e. mechanistic models. This is probably the greatest challenge in the near future of Environmental Mineralogy and Geochemistry.

The present study reports the results of a combined approach which uses morphological characterization, magnetic measurements, and multifrequency electron magnetic resonance (EMR; 9− 285 GHz) to identify and characterize both the bulk and the nanoscale magnetic ...

In this work, we investigated a 3 ha sulphide-bearing waste-rock dump (Libiola Mine, Italy) using mineralogical, geochemical, and geostatistical analyses. The dumped materials were highly heterogeneous in grain size and lithology and varied both laterally and vertically. Other than the host rock of the ore, basalts and serpentinites, the dumped materials contained high amounts of low-grade chalcopyrite- and pyrite-rich mineralisations. Due to these characteristics and to the absence of minerals able to neutralise acidity, this waste-rock dump can be classified as an acid mine drainage (AMD) producer. The study confirms that AMD is still active and, in the best scenario, can persist for up to 6.17 × 103 years. The consequences of this process are of serious environmental concern as it involves strong acidification of the circulating waters, the release of potentially toxic metals into the soil, streams and rivers and the precipitation of huge quantities of secondary Fe-oxides and Fe-oxyhydroxides.

Magnetic hematite (α-Fe2O3) and goethite (α-FeOOH) nanoparticles, formed in the abandoned Libiola Mine (Liguria, Italy) as a result of Acid Mine Drainage (AMD) processes that involved sulfide-bearing rocks and sulfide-rich waste material, were investigated through the study of their magnetic properties in combination with electron paramagnetic resonance (EPR) spectroscopy. Both techniques revealed that the behaviour of the nanominerals involved was predominantly superparamagnetic. In contrast, the bulk antiferromagnetic behaviour of both hematite and goethite was substantially reduced. The observed magnetic properties reflected a great variability in the particle dimensions and confirmed that both nanominerals were the transformation products of a metastable amorphous species. Moreover, two peculiar phenomena were hypothesised: the transformation to hematite may occur before the coarsening of the amorphous transient and hematite and goethite can interconvert without intermediate crystallisation of metastable precursors. Goethite, in fact, appears to be formed as an alteration product of hematite, after a drastic change of the physico-chemical boundary conditions.

... structural and microstructural investigations Cristina CARBONE 1 , Francesco DI BENEDETTO 2 , Pietro MARESCOTTI 1 ,* , Alberto MARTINELLI 3 , Claudio SANGREGORIO 4 ... We further acknowledge Dr. M. Carnasciali for µ-Raman analyses and Prof. R. Basso and Prof. ...

Abstract Squawcreekite is a rare AO 2 oxide with rutile-type structure. A squawcreekite (FeSbO 4)-rutile (TiO 2) solid solution has been recognised in quartz veins from the Kajlidongri manganese mine District Jhabua, Madhya Pradesh (India): this finding ...