... oxidised manganiferous phyllites of Ordovician age at Le Coreux near Salmchâteau, Belgium. Accompanying minerals are hematite, braunite, hollandite-strontiomelane, kanonaite, Mn-oxides, albite and muscovite. Stavelotite-(La) is trigonal, space group P 3 1 , with a = 11.525(2), c = 33.347(9) Å, V = 3836(1...

..., for instance, in priderite. In some cases, structural refinements have been carried out in monoclinic (pseudo-tetragonal) space groups, with a ≈ c ≈ 10.0 Å, and β ≈ 90°, such as I 2/ m ( e.g. , cryptomelane) or P 2 1 / n ( e.g. , strontiomelane). The lowering of symmetry may be related to minor...

... as hollandite) with up to 4 wt% SrO have been reported from Mn deposits ( Perseil 1988 ; Cabella et al. 1995 ) and a piemontite quartzose schist (metachert) ( Banno 1996 ). Strontiomelane, a Sr-analogue of hollandite, was recently reported from the Praborna Mn deposit, Italy ( Meisser et al. 1999...

...+ (strontiomelane). Lower-valence cations (e.g., Mn 3+ , Al 3+ , Fe 3+ , etc.) substitute for some of the Mn 4+ to offset the positive charge of the tunnel cations. Mn hollandite minerals typically contain a variety of tunnel cations. The framework dimensions and consequent tunnel cation coordination environment...

... the systematic absences related to the 2 1 screw axis. As a matter of fact, Capalbo (2013) refined the crystal structure of ferrihollandite from Kajlidongri down to R 1 = 0.032 in the space group P 2/ n . Similarly, the space group symmetry of strontiomelane, given as P 2 1 / n for the 5.8 Å cell...

...° [14] Priderite, K(Ti,Fe 3+ )O 16 I 4/ m a 10.139, c 2.966 Å [12] Akaganéite, FeO(OH) I 2/ m a 10.587, b 3.031, c 10.515 Å, β 90.03° [15] Manjiroite, (Na,K)(Mn 4+ ,Mn 3+ ) 8 O 16 I 4/ m a 9.916, c 2.864 Å [16] Strontiomelane, SrMn 4+ 6 Mn 3+ 2 O 16 P...

... by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA CNMNC), proposal 2019-055 ( Gołębiowska et al. 2019 ). By analogy to cryptomelane and strontiomelane, two other minerals of the coronadite group, the name of the mineral indicates the main...

... ( Fransolet & Bourguignon 1976 , Fransolet 1978 , Hanson 1983 , Fransolet et al. 1984 , Theye & Fransolet 1994 ), and manganese oxides, such as lithiophorite, cryptomelane, nsutite, and hollandite–strontiomelane ( Fransolet 1979 , Schreyer et al. 2001 , Gustine 2002 ). As shown in Figure 2...

... + C u 0.5 2 + O 16 , shows that not all new minerals have a name ending in “-ite”. Thalliomelane is named after its thallium content and its affinity to the dark manganese oxide minerals analogous to the mineral naming scheme of cryptomelane and strontiomelane. Thalliomelane, a new...

... ; Fransolet et al. , 1984 ; Theye & Fransolet, 1994 ), and manganese oxides, such as lithiophorite, cryptomelane, nsutite, and hollandite-strontiomelane ( Fransolet, 1979 ; Schreyer et al. , 2001 ; Gustine, 2002 ). Idaite occurs in several quartz veins in the region of Vielsalm and Fraiture...

....-A. Perseil, J. Brugger, P.-J. Chiappero (1999) Strontiomelane, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(SrMn_{6}^{4+}Mn_{2}^{3+}O_{16}\) \end{document} , a new mineral species...

... ( Kenngott, 1853 ) and strontiomelane ( Meisser et al. , 1999 ) have been described, in addition to the spectacular colour varieties of pyroxene, phengite, titanite, etc. (e. g . Mottana et al. , 1979 ). The situation and structure of the deposit, with a layered oxidized quartzite horizon containing...

...–Al 2 O 3 –SiO 2 –H 2 O . in “ Progress in metamorphic and magmatic petrology ”, L.L. Perchuk , ed. Cambridge University Press , UK , 47 – 64 . Schreyer , W. , Fransolet , A.-M. , Bernhardt , H.-J. ( 2001 ): Hollandite-strontiomelane solid solutions coexisting...

... present. The main minerals include quartz, braunite, hematite, spessartine, piemonite, locally ardennite, pyroxmangite, rhodonite, tephroite, friedelite, and humite-group minerals. The Praborna mine is the type locality for roméite, piemonite and strontiomelane. Manganiandrosite-(Ce) was collected...

.... Fransolet A.-M. Bernhardt H.-J. ( 2001 ) Hollandite-strontiomelane solid solutions coexisting with kanonaite and braunite in late quartz veins of the Stavelot Massif, Ardennes, Belgium . Contributions to Mineralogy and Petrology 141 , 560 – 571 . Schryer W. Bernhardt H.-J...

... ; Tumiati, 2005 ; Cenki-Tok et al ., 2006 ). Praborna is the type locality for a score of mineral species, namely piemontite, braunite, romeite, manganian-drosite-(Ce) and strontiomelane ( Ciriotti et al ., 2009 ). The manganese deposit of Praborna is composed of a boudinaged quartz-rich layer, which...

... P.J. ( 1999 ) Strontiomelane, SrMn 4+ 6 Mn 3+ 2 O 16 , a new mineral species of the cryptomelane group from St. Marcel-Praborna, Aosta valley, Italy . The Canadian Mineralogist , 37 , 673 – 678...

... phyllites at Le Coreux, 1 km north of Salmchâteau, Belgium. It is associated with albite, braunite, hematite, hollandite-strontiomelane, kanonaite, Mn-oxides, and muscovite. The name is for the Stavelot Massif in the Belgian Ardennes Mountains, and Stavelot, which is a historical town in eastern Belgium...

... on these tunnel cations are offset by substitution of lower valence cations, typically Mn 3+ , Al 3+ , and Fe 3+ , for the Mn 4+ in the octahedral framework. The predominant tunnel cation determines the particular mineral: hollandite (Ba 2+ ), cryptomelane (K + ), strontiomelane (Sr 2+ ), coronadite (Pb 2...