The new mineral topsøeite, FeF3(H2O)3, was found as a fumarolic product after the 1991 eruption of Hekla, Iceland. The mineral occurs as up to 20 µm large square-prismatic crystals forming occasional stepped aggregates or massive, up to 100 µm wide veins, in association with several other fluorides, hematite and opal. The experimental formula of the mineral (from scanning electron microscope energy-dispersive spectrometry data) is Fe(F2.94Cl0.04)Σ2.98(H2O)1.94. The deficiency of water in the formula is most probably an artefact due to experimental limitations and not a sign of dehydration. The mineral is yellow, with a calculated density of 2.330 g·cm−3, based on the ideal formula. It is tetragonal (P4/n) with a = 7.8381(3) Å, c = 3.8674(1) Å, V = 237.60(2) Å3. The strongest eight powder diffraction lines are [d in Å (relative intensity) (hkl)]: 5.55 (100) (1 1 0); 3.92 (43) (0 2 0); 3.47 (39) (0 1 1); 3.17 (22) (1 1 1); 2.77 (30) (2 2 0); 2.479 (31) (1 3 0, 3 1 0); 1.877 (16) (0 1 2), 1.753 (24) (2 4 0, 4 2 0). Rietveld refinement of the powder diffraction data confirmed the identity of topsøeite with synthetic β-FeF3(H2O)3. The crystal structure consists of straight infinite chains of [FeF4(H2O)2] octahedra extending along the c axis. The adjacent octahedra share apical F atoms, whereas the four unshared, equatorially coordinated atoms are represented by a disordered arrangement of two F and two O atoms from water molecules. Additional water molecules occupy the spaces between chains and are tetrahedrally coordinated by four (F, H2O) from four different chains binding them together via hydrogen bonds. Topsøeite is isostructural with rosenbergite, AlF3(H2O)3. Both minerals have rhombohedral polymorphs known from studies of phase systems. The polymorph of topsøeite (UM2008-27-F:AlHO), earlier supposed to be aluminium fluoride hydrate, was also found in Hekla fumaroles from the 1991 eruption, but its genetic relation with topsøeite remains unclear. Topsøeite is named after the family of Danish prominent scientists and industrialists including Haldor Topsøe the elder (1842–1935), Haldor Topsøe the younger (1913–2013) and Henrik Topsøe (1944).
Skip Nav Destination
Article navigation
Research Article|
July 01, 2018
Topsøeite, FeF3(H2O)3, a new fumarolic mineral from the Hekla Volcano, Iceland
Tonči Balić-Žunić;
Tonči Balić-Žunić
1
Department of Geosciences and Natural Resource Management, University of Copenhagen
, Øster Voldgade 10, 1350København K, Denmark
Search for other works by this author on:
Anna Garavelli;
Anna Garavelli
2
Dipartimento di Scienze della Terra e Geoambientali, Università degli Studi “A. Moro” di Bari
, via E. Orabona 4, 70125Bari, Italy
3
Centro Interdipartimentale “Laboratorio di Ricerca per la Diagnostica dei Beni Culturali”
, via E. Orabona 4, 70125Bari, Italy
Search for other works by this author on:
Donatella Mitolo
Donatella Mitolo
4
Autorità di Bacino della Puglia, c/o Innovapuglia
, Str. Prov. per Casamassima 3, 70100Valenzano, BA, Ital
y
Search for other works by this author on:
European Journal of Mineralogy (2018) 30 (4): 841–848.
Article history
received:
17 Jun 2017
rev-recd:
28 Sep 2017
accepted:
08 Oct 2017
first online:
04 May 2018
Citation
Tonči Balić-Žunić, Anna Garavelli, Donatella Mitolo; Topsøeite, FeF3(H2O)3, a new fumarolic mineral from the Hekla Volcano, Iceland. European Journal of Mineralogy 2018;; 30 (4): 841–848. doi: https://doi.org/10.1127/ejm/2018/0030-2751
Download citation file:
You could not be signed in. Please check your email address / username and password and try again.
Index Terms/Descriptors
Latitude & Longitude
Citing articles via
Related Articles
T – Goldschmidt Abstracts 2013
Mineralogical Magazine
N – Goldschmidt Abstracts 2013
Mineralogical Magazine
D – Goldschmidt Abstracts 2013
Mineralogical Magazine
Jakobssonite, CaAlF5, a new mineral from fumaroles at the Eldfell and Hekla volcanoes, Iceland
Mineralogical Magazine
V – Goldschmidt Abstracts 2013
Mineralogical Magazine
LEONARDSENITE, MgAlF5(H2O)2, A NEW MINERAL SPECIES FROM ELDFELL VOLCANO, HEIMAEY ISLAND, ICELAND
The Canadian Mineralogist
Related Book Content
The petrogenetic and metallogenetic significance of topaz granite from the southwest England orefield
Ore-bearing Granite Systems; Petrogenesis and Mineralizing Processes
The Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy
Elements of Pennsylvanian Stratigraphy, Central Appalachian Basin
Oil-sands clays
Introduction to Oil Sands Clays
Oil-sands clays
Introduction to Oil Sands Clays
Sustainability in earthen heritage conservation
Sustainable Use of Traditional Geomaterials in Construction Practice
Atmospheric halogen and acid rains during the main phase of Deccan eruptions: Magnetic and mineral evidence
Volcanism, Impacts, and Mass Extinctions: Causes and Effects