Options
Demartin, Francesco
Loading...
Preferred name
Demartin, Francesco
Main Affiliation
13 results
Now showing 1 - 10 of 13
- PublicationRestrictedLeonardsenite del Vesuvio (secondo ritrovamento mondiale)(2013)
; ; ; ;Campostrini, I.; Dipartimento di Chimica - Univerità di Milano ;Demartin, F.; Dipartimento di Chimica - Univerità di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; As a part of the scientific agreement between the Dipartimento di Chimica - Università degli Studi di Milano and the Osservatorio Vesuviano (Napoli), the content of the bottles belonging to the historical collection of the Osservatorio, most of them collected before the 1944 eruption, was examined. The study allowed to identify several new phases, among which the recently described d’ansite-(Mn). In samples collected by A. Malladra in 1920, leonardsenite, MgAlF5(H2O)2, was identified. The mineral occurs as minute colorless prismatic crystals, wit maximum size of about 100 microns. The identification was obtained by single-crystal X-ray diffraction. The unit-cell data are: a 7.083(3); b 10.155(4); c 6.816(3) Å. This is the second discovery in the world.195 29 - PublicationRestrictedI minerali di origine fumarolica dei Campi Flegrei : Solfatara di Pozzuoli (Napoli) e dintorniL'area dei Campi Flegrei situata a nord della città di Napoli è caratterizzata da un vulcanismo che si è esplicato negli ultimi 80.000 anni sia con potenti eruzioni altamente esplosive (tanto da farlo definire un super vulcano)....
475 99 - PublicationRestrictedD’ansite-(Mn), Na21Mn2+(SO4)10Cl3 and d’ansite-(Fe), Na21Fe2+(SO4)10Cl3, two new minerals from volcanic fumaroles(2012)
; ; ; ; ; ;Demartin, F.; Dipartimento di Chimica, Universita` degli Studi di Milano, ;Campostrini, I.; Dipartimento di Chimica, Universita` degli Studi di Milano, ;Castellano, C.; Dipartimento di Chimica, Universita` degli Studi di Milano, ;Gramaccioli, C.M.; Dipartimento di Chimica, Universita` degli Studi di Milano, ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; The new minerals d’ansite-(Mn), Na21Mn2+(SO4)10Cl3, and d’ansite-(Fe), Na21Fe2+(SO4)10Cl3, occur as encrustations in fumaroles at Vesuvius, Naples, Italy and La Fossa crater, Vulcano, Aeolian Islands, Italy, respectively. Both minerals are cubic and crystallize in space group I4¯ 3d. D’ansite-(Mn) forms colourless translucent tristetrahedral crystals up to 0.2 mm on edge; d’ansite-(Fe) forms aggregates of colourless to white complex isometric crystals of about the same size. Chemical analyses obtained by energy-dispersive spectrometry on an electron microprobe gave the following mean compositions: d’ansite-(Mn), Na2O 39.37, MnO 3.46, MgO 0.13, SO3 49.99, Cl 6.36, O=Cl 1.44, total 97.87 wt.%, c o r r e s p o n d i n g t o a n e m p i r i c a l f o r m u l a , on t h e ba s i s o f 43 a n i o n s , of Na20.61(Mn2+ 0.79Mg0.05)S0.84S10.13O40.09Cl2.91; and d’ansite-(Fe), Na2O 39.12, FeO 4.18, MgO 0.12, SO3 49.91, Cl 6.81, O=Cl 1.54, total 98.60 wt.%, corresponding to an empirical formula of Na20.42(Fe2+ 0.94Mg0.05)S0.99S10.08O39.89Cl3.11. The six strongest reflections in the X-ray powder diffraction pattern of d’ansite-(Fe) [listed as dobs(A˚) (I) (hkl)] are as follows: 2.807(100)(044), 2.570(37)(235), 1.714(29)(129), 3.384(27)(233), 3.113(26)(134), 2.108(15)(237). The unit-cell parameters obtained from single-crystal data are 15.9291(9) and 15.882(3) A ˚ for d’ansite-(Mn) and d’ansite-(Fe), respectively. The structure of both minerals was refined, using single-crystal diffraction data, to final R parameters of 0.0309 and 0.0336 on reflections with I > 2s(I). The structure contains three independent Na sites, one of which is partially occupied by Mn2+ or Fe2+, two independent sulfate anions and one chlorine site.167 21 - PublicationRestrictedKottenheimite,Ca3Si(SO4)2(OH)6 .12H2 0, della cava Montenero di Onano (Viterbo,Lazio): secondo ritrovamento mondialeNella Cava di Montenero di Onano, sita nel bacino di Latera in provincia di Viterbo(Lazio), è stata rinvenuta in un proietto lavico una rara specie in ottime cristallizzazioni: la kottenheimite...
147 28 - PublicationOpen AccessSbacchiite, Ca2AlF7, a new fumarolic mineral from the Vesuvius volcano, Napoli, ItalyThe new mineral sbacchiite (IMA 2017-097), Ca2AlF7, was found in a fossil fumarole (1944 eruption, T ! 80 !C) at the rim of the crater of the Vesuvius volcano, Napoli, Italy, associated with gearsksutite, usovite, creedite and opal. It forms elongated crystals up to about 60 lm in length. On the basis of powder X-ray diffraction data and chemical analysis, the mineral was recognized to be identical to the corresponding synthetic phase. Crystals are transparent or translucent and colourless, with vitreous lustre and white streak. The tenacity is brittle. The measured density is 3.08(2) g/cm3, the calculated density is 3.116 g/cm3. The empirical formula, (based on 10 atoms per formula unit, apfu) is Ca2.02Mg0.03Al0.99F6.97. Sbacchiite is orthorhombic, space group Pnma, with a = 7.665(2), b = 6.993(1), c = 9.566(2) Å, V = 512.2(2) Å3 and Z = 4. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 3.840(45)(200), 3.563(85)(201), 3.499(100)(020), 2.899(55)(013), 2.750(30)(212), 2.281(20)(104), 2.255(52)(302) and 2.173(36)(131). The structure was refined to R = 0.0479 for 457 reflections with I > 2r(I). The asymmetric unit contains one Al3+ and two independent Ca2+ cations and five fluorine anions. Aluminium is octahedrally coordinated by six fluorine atoms; the arrangement of F around the 7-coordinated Ca(1) conforms to a distorted pentagonal bipyramid and that around Ca(2) to a very distorted polyhedron (in 7 + 1 coordination). All the fluorine atoms are threefold coordinated. The structure framework shows ‘‘isolated’’ [AlF6] octahedra, whereas the coordination polyhedra around Ca are linked by common edges [sequence: Ca(1)–Ca(2)– Ca(1). . .] along [010] and the same holds for the connection along [001]. Along [100], however, only the pentagonal bipyramids around Ca(1) are connected by bridging corners.
72 77 - PublicationOpen AccessNEW MINERAL SPECIES FROM VULCANO, AEOLIAN ISLANDS, SICILY, ITALY(2011-09)
; ; ; ; ;Campostrini, I.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Demartin, F.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Gramaccioli, C.M.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; Since 2006 Vulcano Island was the object of a joint project concerning the study of fumarole minerals of Italian volcanoes, carried out in collaboration with Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli - Osservatorio Vesuviano. At present, the mineral species found at Vulcano are over 100; the island is the type locality for 23 species, 17 of which were discovered by us, and it is the unique occurrence for 20 of them. Besides the already IMA-approved “official” species, there are at least 38 potentially new minerals currently under examination. By far the main occurrence for these minerals are the fumaroles located...148 101 - PublicationOpen AccessParascandolaite, IMA 2013-092.(2013)
; ; ; ; ;Campostrini, I.; Dipartimento di Chimica - Univerità di Milano ;Demartin, F.; Dipartimento di Chimica - Univerità di Milano ;Castellano, C.; Dipartimento di Chimica - Università di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; The new mineral parascandolaite is the natural analog of the synthetic fluoride KMgF3. It was found as a volcanic sublimate at Vesuvius volcano on 1944 eruption.160 254 - PublicationRestrictedParascandolaite, KMgF3, a new perovskite-type-fluoride from Vesuvius(2014)
; ; ; ; ;Campostrini, I.; Dipartimento di Chimica - Univerità di Milano ;Demartin, F.; Dipartimento di Chimica - Univerità di Milano ;Castellano, C.; Dipartimento di Chimica - Università di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; The new mineral parascandolaite, isotypic to cubic perovskites, space group Pm3m (no. 221) is the natural analog of the synthetic fluoride KMgF3 and is related to neighborite, NaMgF3. It was found as a volcanic sublimate at Vesuvius volcano on 1944 eruption lava scoria, associated with opal, cerussite, mimetite, phoenicochroite and coulsellite. It occurs as transparent colorless to white cubic crystals up to 0.5 mm in length with vitreous luster. The density measured by flotation in a diiodomethane–toluene mixture is 3.11(1) g/cm3; that calculated from the empirical formula and single-crystal X-ray data is 3.123 g/cm3. The mineral is isotropic with n = 1.395(5) (580 nm). The six strongest reflections in the X-ray powder diffraction pattern are: [dobs in Å(I)(h k l)] 2.001(100)(2 0 0), 2.831(83) (1 1 0), 2.311(78)(1 1 1), 1.415(56)(2 2 0), 1.633(35) (2 1 1) and 1.206(22)(3 1 1). The unit-cell parameter is a = 4.0032(9) Å. The structure was refined to a final R(F) = 0.0149 for 35 independent observed reflections [I > 2σ(I)]. The mineral is named after the Italian mineralogist Antonio Parascandola (1902–1977).254 63 - PublicationOpen AccessD’ansite-(Mn), IMA 2011-064. CNMNC Newsletter No. 11, December 2011(2011)
; ; ; ; ; ;Campostrini, I.; Dipartimento di Chimica, Università di Milano ;Demartin, F.; Dipartimento di Chimica, Università di Milano ;Castellano, C.; Dipartimento di Chimica, Università di Milano ;Gramaccioli, C.M.; Dipartimento di Chimica, Università di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; Mn2+-analogue of d'ansite161 133 - PublicationOpen AccessTHE OCCURRENCE OF LAFOSSAITE AT VESUVIUS(2011-09)
; ; ; ; ;Campostrini, I.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Demartin, F.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Gramaccioli, C.M.; Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano ;Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; As a part of a joint project concerning the study of fumarole minerals of the Italian volcanoes, carried out in collaboration with the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli - Osservatorio Vesuviano, a systematic investigation of old fumarole mineral samples was undertaken. The presence of natural thallium chloride lafossaite, first described at La Fossa crater...145 82