...J. Plášil; R. Škoda Abstract Marécottite, ideally Mg 3 [(UO 2 ) 4 O 3 (OH)(SO 4 ) 2 ] 2 (H 2 O) 28 , a triclinic, Mg-dominant member of the zippeite group, was described originally from a small uranium deposit at La Creusaz in Wallis (Switzerland). It has recently been found at Jáchymov (Czech...

.... The zippeite-group of minerals is one of the most common and diverse in such settings. To decipher the nature and crystal chemistry of the zippeite-group, the crystal structure of a new natural hydrated Mg uranyl sulfate related to Mg-zippeite was determined. The mineral is named marecottite after the type...

... in the Plavno mine, in the eastern part of the Jáchymov ore district, Western Bohemia, Czech Republic, where it occurs as a supergene alteration phase formed by hydration–oxidation weathering of uraninite in hydrothermal U-veins. It was found to be associated with marécottite, magnesiozippeite, blatonite...

...F ig . 10. Polyhedral representations of the structures of magnesium-zippeite (a), SZIPPMg (b), and marecottite (c). ...

... ), ammoniozippeite ( Kampf et al. 2018b ), natrozippeite ( Burns et al. 2003 ), uranopilite ( Burns 2001 ), ammoniomathesiusite ( Kampf et al. 2019c ), johannite ( Donnay 1955 ; Mereiter 1982 ), marécottite ( Brugger et al. 2003 ; Burns et al. 2003 ), lussierite ( Kampf et al. 2019b ), zincorietveldite ( Kampf et...

... as interlayer cations in the zippeite species: zippeite, natrozippeite, magnesozippeite, cobaltzippeite, zinczippeite, nickelzippeite, rabejacite, marécottite, sejkoraite-(Y), and pseudojohannite ( Brugger et al . 2003 , 2006 , Frondel et al . 1976 , Plášil et al . 2011a , 2013 , 2014a , b, Vochten et...

..., the Mg octahedra share one vertex (O Ur ) with the sheet at either side (magnesium-zippeite, Burns et al. 2003 ), in the second case the octahedra only share a vertex (O Ur ) with one of the two adjacent sheets, and in the third case (marecottite, Brugger et al . 2003 ), no vertex is shared...

... pentagonal bipyramids, two polyhedra wide, which are linked by sharing vertices with sulfate tetrahedra. This arrangement results in a U:S molar ratio of 2. Brugger et al. (2003) described the new mineral species marécottite from the La Creusaz deposit, Switzerland, nominally Mg 3 (H 2 O) 18 [(UO 2 ) 4...

... Data Publishing , Tucson, Arizona . Brugger , J. , Burns , P.C. and Meisser , N. ( 2003 ) Contribution to the mineralogy of acid drainage of uranium minerals: Marecottite and the zippeite-group. American Mineralogist , 88 , 676 – 685 . Burns , P.C. ( 2001 ) A new...

...-strength bond length curves for oxides . Acta Crystallographica , A29 , 266 – 282 . Brugger J. Burns P.C. Meisser N. ( 2003 ) Contribution to the mineralogy of acid drainage of uranium minerals: Marécottite and the zippeite group . American Mineralogist , 88 , 676 – 685...

..., marecottite). In the interlayer of these minerals, there are additional layers of (H 2 O) groups that do not bond to any interstitial cation ( Locock & Burns 2003c , d , Locock et al. 2004a , 2005 , Brugger et al. 2003 ). Many of these minerals are not stable in air and dehydrate to phases...

... N. and Burns P.C. ( 2003 ) Contribution to the mineralogy of acid drainage of uranium minerals: marecottite and the zippeite-group . American Mineralogist , 88 , 676 – 685...

... , J. , Meisser , N. and Burns , P.C. ( 2003 ) Contribution to the mineralogy of acid drainage of uranium minerals: marécottite and the zippeite-group . American Mineralogist , 88 , 676 – 685 . Brugger , J. , Wallwork , K.S. , Meisser , N. , Pring , A. , Ondruš...