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kircherite (IMA 2009-084), a new member of the cancrinitesodalite group of minerals from Valle Biachella, Sacrofano, (Rome), in the Sabatini volcanic complex, Latium, Italy. The mineral occurs within miarolitic cavities of holocrystalline, syenitic, volcanic ejecta, associated with sodalite, biotite, iron oxides, titanite, fluorite, and a pyrochlore group mineral. The groundmass of the ejecta consists essentially of potasiumfeldspar, with minor sodalite and brown mica. Kircherite occurs typically as parallel associations of hexagonal, thin, tabular crystals (2 or 3 mm in diameter and 1 mm in thickness). Single platelets have a thickness that very rarely exceeds 0.5 mm. Crystals are colourless to light gray to white, translucent to opaque in the most altered parts of the crystals; lustre is greasy to silky. Fluorescence is in light pink under LW UV and deep red under SW UV. Hardness is (Mohs): 5.5; micro-indentation VHN load 10 g, mean 648.4 kg mm-2, range ± 208.9 kg mm-2. Cleavage on {001} is good. Density (calc.) is 2.457 g cm-3. Kircherite is non-pleochroic and uniaxial negative with ω = 1.510(2), ε = 1.502(2). Kircherite is trigonal, space group R32, with , a = 12.8770(7) Å, c = 95.224(6) Å, V = 13677.2(13) Å3, Z = 1. The empirical chemical formula obtained from EMP analyses is: (Na89.09Ca31.63K18.85Fe0.20Mn0.06Mg0.05Ti0.03)Σ=139.91 (Si108.13 Al107.87)Σ=216.00O430.08(SO4)32.59 Cl2.00F0.53(CO3)0.09·6.86H2O, which corresponds to the ideal formula [Na90Ca36K18]Σ=144 (Si108Al108O432)(SO4)36·6H2O. The strongest six reflections in the X-ray powder pattern are [d in Å (I %) (hkl)]: 3.72 (100) (300), 2.65 (100) (2.1.28; 0.0.36), 3.23 (65) (2.1.19), 3.58 (60) (1.2.14), 3.60 (53) (1.0.25), 3.80 (52) (1.2.11). The single-crystal FTIR spectrum rules out OH groups and shows the presence of H2O and CO2 molecules in the structural cages of the mineral. The structure can be described as a stacking sequence of 36 layers of six-membered rings of tetrahedra along the c axis as ACABCABCABCACBCABCABCABCBABCABCABCAB…, where A, B and C represent the positions of the rings within the layers. The structure has 6 cancrinite cagϵe)s, 2(4 sodalite cages (S) and 6 LOSOD cages (L) within the unit cell, and these account for a maximum of 36 SO4 2- groups and 6 H2O molecules (or Cl anions). There is a unique sequence of cages, ϵSSSLSSLSSSϵ and adjacent sequences are shifted 1/3 along [001]. Kircherite, having 36 layers, is the cancrinite with the longest complex sequence described to date. The name is for Athanasius Kircher (1602–1680), a German Jesuit who was the founder of the museum of the Collegium Romanum in 1651, hereafter named the Museum Kircherianum.

Il progetto SMART ENVIRONMENTS, svoltosi negli anni dal 2015 al 2017 presso l’Ateneo Roma Tre, è stato finanziato dalla Regione Lazio con lo scopo di sostenere l’attività di ricerca orientata all’accrescimento della competitività tecnologica del tessuto imprenditoriale della regione e di promuovere il sistema della ricerca e innovazione mediante la valorizzazione delle infrastrutture di ricerca presenti sul territorio. Un indirizzo che aveva, fin da subito, individuato nel trasferimento tecnologico una delle chiavi in grado di sostenere lo sviluppo industriale della Regione Lazio in un periodo difficile dove però la possibile ripresa economica garantiva disponibilità di investimenti. SMART ENVIRONMENTS, con la sua dichiarata progettualità a forte vocazione imprenditoriale, è andato a esplorare, quindi, il nuovo terreno della Terza Missione delle Università, dove il rapporto con il territorio finisce al centro dell’operare accademico non più in una ottica di diffusione del sapere che procede dall’alto verso il basso ma con la pretesa di lavorare insieme al tessuto produttivo, sia esso industriale, di servizio o culturale, per coadiuvare le imprese nel difficile compito di rinnovamento tecnologico e di idee rimanendo al contempo fecondati dalle esigenze sociali e di mercato.

In this work we report on a complete crystal-chemical characterization of a near end-member riebeckite from Malawi, and use the available data to critically compare information obtained from different analytical methods. The sample occurs as well-formed and very large single crystals in pegmatitic rocks. Accurate site-populations were determined by combining single-crystal structure refmement and electron microprobe analysis (EMPA). The Fe3+ /Fe2+ ratio was obtained from Mossbauer spectroscopy. Lithium was quantified by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS).

In the archaeological Khmer complex (Cambodia), an unusual black patina covering both the exterior and interior walls of the Neang Khmau temple, has been observed during a recent conservative survey. In fact, it is present over all the four facades of the temple, covers a relevant part of the vertical surfaces protected from rainfall and is also homogeneously distributed on the interior of the monument. The upper and the lower areas show, on the contrary, a relevant lichen growth. The temple was built by using laterite bricks, a natural material common in tropical areas as a weathering product of pre-existing rocks. A preliminary investigation on the patina samples together with ecological considerations excluded a biological origin of the black alteration, thus prompting a more detailed study. In this work, we have investigated the physico-chemical origin of this unusual patina by identifying its mineralogical and chemical composition. Raman and FTIR spectroscopies, SEM-EDS, micro-XRF and XRPD have been applied to characterize the alteration products. Analyses have been performed both on single fragments and on polished cross sections collected from all four temple facades and from one area in the temple interior. Optical observations of the cross sections have evidenced irregularities in the thickness of the patina. Raman and FTIR spectra have revealed that the black layers are mainly composed of manganese minerals (hollandite, romanechite and manganite). This peculiar alteration pattern is interpreted as because of the tropical climatic conditions of Cambodia. Indeed the variation of wet and dry seasons favours the migration of iron and manganese ions and their successive immobilization in regions not directly subject to leaching.

Opals are naturally occurring hydrous silica materials (SiO2*nH2O), characterized by different degrees of crystallinity and crystal structure. Because of their optical properties, opals have been largely used in jewelry and as decorative elements in artworks. For this reason, a complete characterization and a provenance study of this kind of materials is mandatory in order both to avoid frauds and to reconstruct ancient and modern trade routes of gems. In this work, we present a combined spectroscopic (Raman, FTIR) and X-ray powder diffraction (XRD) investigation of nine opals from the main deposits around the world (Australia, Madagascar, Slovakia, Mexico, Honduras and Ethiopia). Four of these samples are the rare and precious fire opals, characterized by an intense red–orange color. Ethiopia, Honduras and Mexico opals showed spectra and diffraction patterns typical of Opal-CT, generally associated to volcanic genesis, while Australia, Madagascar and Slovakia opals are Opal-A type, associated to sedimentary origin. Unexpectedly the fire opal from Brazil behaves as a CT one. The presence of CO2 was detected only in the latter group, and exceptionally in the Honduras sample; FTIR-FPA imaging showed carbon dioxide to be homogeneously distributed inside the gems. Opals-CT are CO2-free and give much more complex FT-IR spectra in the NIR region where H2O combination modes occur. The obtained results are discussed in terms of relevance of the above experimental techniques for geosourcing opals, and contribute to increase the database of the chemical–physical properties of opals.

This work reports the synthesis and crystal-chemistry of ferri-clinoferroholmquistite in the system Li(2)O - FeO - Fe(2)O(3) - SiO(2) - H(2)O. Ferri-clinoferroholmquistite has a very restricted temperature stability. An almost monophase amphibole product is obtained at 500degreesC for a wide pressure range (1-7 kbar), whereas a Li-bearing pyroxene becomes predominant for T greater than or equal to 600degreesC. The X-ray powder pattern of ferri-clinoferroholmquistite was indexed in the C2/m space group. Refined cell dimensions are: a = 9.489 (2), b = 18.036 (7), c = 5.313 (3) Angstrom; beta = 101.59 (3). Infrared spectra in the OH-stretching region show the presence of a single and very sharp band at 3614 cm(-1), which is assigned to the Fe(2+)Fe(2+)Fe(2+) trimer at the OH-coordinated M1M1M3 octahedra, and a small satellite band at 3644 cm(-1) which was assigned to Li at M3. Mossbauer spectra can be fitted to three doublets assigned to Fe(3+) at M2, Fe(2+) at M1 and Fe(2+) at M3, respectively, with a calculated Fe(2+)/Fe(2+) ratio of 2/3, suggesting a composition close to the nominal one. The spectroscopic data show that synthetic ferri-clinoferroholmquistite has a strongly ordered cation distribution, in agreement with single-crystal refinements done by Caballero et al. (1998) and Oberti et al. (2000) on natural samples with related Li-rich compositions.

This work relates the occurrence and the characterization of fibrous tremolite within the latest pyroclastic deposits of the Colli Albani (Alban Hills) volcano, to the south-east of Rome (Italy). These mineralizations were observed during a systematic rock sampling undertaken to complete the geological survey for the new 1:50,000 map of this volcanic area. The examined specimens were collected inside distal deposits correlated to the last Albano Maar activity, which are geographically located within the boundaries of the Nemi community. Tremolite occurs within both carbonate ejecta and the host pyroclastic rocks. It shows up as whitish to light grey-coloured aggregates of crystals with fibrous aspect and sericeous brightness. Due to the extremely small crystal dimensions, never exceeding 0.5 mu m in diameter, the micro-chemical composition of the fibres could be obtained only by combining P-XRD, SEM-EDX and FTIR methods. Infrared spectroscopy, in particular, proved to be a valuable technique to characterize the studied amphibole. The composition determined is that of a Fe-free F-rich (c. 53 %) tremolite with significant (c. 20 %) richterite components in solid solution. The occurrence of fibrous tremolite in an inhabited place, occurring as natural geological material rather than being due to anthropogenic pollution, should be examined with concern, because it implies complex health and legal responsibilities in the case of mobilization due to extreme climatic events.