...Marco E. Ciriotti Abstract Churchite-(Nd) and iodine, up to now recognized as valid minerals by IMA CNMNC, are discredited because, for different reasons, both are non-existent mineral species and were never actually characterized. Churchite-(Nd) is in fact neodymium-rich churchite-(Y) and iodine...

...Fig. 7 Representative REE patterns of rhabdophane and churchite (determined by EMPA) and bastnäsite (determined by LA–ICP–MS). ...

...Ştefan Marincea; Delia-Georgeta Dumitraş Abstract In a recent work, Onac and White (2003) reported on berlinite, but also chlorellestadite and churchite, from the Bivouac Room, Cioclovina Cave, Romania. Our analyses of materials collected from this site failed to identify berlinite...

... hydrothermal conditions to complex mineral aggregates (stubby kolbeckite II) produced under weathering conditions. The latest supergene alteration consists of wavellite, beraunite, cacoxenite, strengite, P- and Mn-bearing “limonite”, autunite, Sc-bearing vochtenite, Sc-bearing churchite-(Y) and diadochite...

... description by Onac et al . (2002 , 2005) and Onac & White (2003) of some “exotic” mineral species such as berlinite, burbankite, churchite-(Y), ellestadite-(OH), ellestadite-(Cl), foggite, paratacamite, collinsite and sampleite, led to the Discussion by Onac & Effenberger presented above...

...– complexing allowed the REE to be redistributed without fractionation; and (3) secondary REE mineralisation was dominated by minerals such as HREE -enriched fluorocarbonates, xenotime-(Y) and churchite-(Y) whose crystal structures tends to favour HREE . * Author for correspondence: Delia Cangelosi...

... this occurrence, foggite, churchite-(Y) and colourless or milky-white needle-like brushite and gypsum were also documented. The empirical formula (calculated from the electron-microprobe results on the basis of five carbonate groups pfu ) is (Na 2.46 Ca 0.98 Sr 1.71 Ba 0.32 Y 0.05 Ce 0.17 La 0.08 Nd 0.08 Pr 0.02...

...Fig. 5. Representative TEM images showing the microstructure of hydrothermal REE phosphates by alteration of fluorapatite. (a, b) BF images showing variously oriented submicrometric crystallites of rhabdophane-(Y) [Rhb-(Y)] and churchite-(Y) [Chu-(Y)], with domain boundaries marked by yellow...

... to transform to perrierite above 600° C., and CeO 2 forms from both minerals at higher temperatures. Weathering products associated with perrierite include anatase, churchite, cerianite, bastnaesite, as well as minerals very close to ancylite and florencite. 25 1 1966 10 2 1966 Copyright ©...

..., monetite, crandallite, and taranakite (Constantinescu et al . 1999, Onac et al . 2002, Marincea & Dumitraş 2003, Dumitraş et al . 2004) are accompanied by a number of rare mineral species such as tinsleyite, sampleite, paratacamite or clinoatacamite, churchite-(Y), and foggite (Marincea et al...

..., Ca(PO 3 OH)· 2H 2 O, for churchite-(Y), YPO 4 ·2H 2 O, and of hydroxyl-apatite, Ca 5 (PO 4 ) 3 (OH), for chlorellestadite, Ca 5 [(Si,P,S)O 4 ] 3 (Cl,OH,F), was assumed by Marincea and Dumitraş (2005) ; however, shifts opposite from those observed are required for these mineral pairs. Due...

...) 2 ]O 2 (OF). IMA 15-C: Churchite-(Nd) (discredited) Proposal 15-C is accepted, and churchite-(Nd) is officially discredited. IMA 15-D: Iodine (discredited) Proposal 15-D is accepted, and iodine is officially discredited. ...

... Romanechite Pumpellyite-(Mg) Pyrochlore or microlite Mixture Berzeliite Tremolite Hematite Magnesio-riebeskite or magnesio-arfvedsonite Rhodonite Magnesio-riebeckite Bariomicrolite Hornblende Churchite Alpha-quartz Rutherfordine Hureaulite + jahnsite Plumbian uranpyrochlore Phoenicochroite Schmiederite...

... chemical relationship of these minerals with churchite-(Y), and its potential connection with other Ca, U 4+ , REE-phosphate mineral equilibria cannot be ignored, although it adopts an entirely distinctive crystal structure ( Kohlmann et al. 1994 ). Notwithstanding, both the structural and WDS...