...Martin Ondrejka; Peter Bačík; Marián Putiš; Pavel Uher; Tomáš Mikuš; Jarmila Luptáková; Štefan Ferenc; Alexander Smirnov ABSTRACT A unique assemblage of hedyphane-group minerals of the apatite supergroup associated with galena, cerussite, and calcite occurs in a Permian aplite dike crosscutting...

... into five groups, based on crystal-chemical arguments: apatite group, hedyphane group, belovite group, britholite group, and ellestadite group. The abundance of distinct ions which may be hosted at the key-sites [M = Ca 2+ , Pb 2+ , Ba 2+ , Sr 2+ , Mn 2+ , Na + , Ce 3+ , La 3+ , Y 3+ , Bi 3+ ; T = P 5...

...Gregor Markl; Michael A.W. Marks; Johannes Holzäpfel; Thomas Wenzel Abstract More than 150 samples of pyromorphite, mimetite, vanadinite, and minerals of the hedyphane-group (which collectively are summarized here under the term PyGM for pyromorphite-group minerals) from the Schwarzwald mining...

... parameters refined from single-crystal X-ray diffraction data are: a = 9.6101(2) Å, c = 7.1311(1) Å, V = 570.35(3) Å 3 and Z = 2. It is isostructural with hedyphane-group minerals, and contains different prevailing (species-defining) Ca and Sr cations at the Ca1 and Ca2 sites, respectively. Fluorsigaiite...

... (AsO 4 ) 3 Cl 9.92 6.86 585.2 P 6 3 / m [4] Hedyphane group  Hedyphane Ca 2 Pb 3 (AsO 4 ) 3 Cl 10.14 7.18 639.8 P 6 3 / m [5]  Hydroxylhedyphane Ca 2 Pb 3 (AsO 4 ) 3 OH 10.04 7.28 635.3 P 3 ¯ [6]  Morelandite Ca 2 Ba 3 (AsO 4 ) 3 Cl 10.17 7.32 655.1 P...

..., and phosphohedyphane. No stable solid solutions appear to exist between the joins phosphohedyphane-hedyphane and chlorapatite-turneaureite in natural systems. Phosphohedyphane new mineral crystal structure chemical analysis solid solution pyromorphite apatite group Dating back to the discovery...

... 2010 21 04 2010 © 2011 American Mineralogist 2011 Fluorphosphohedyphane new mineral crystal structure apatite supergroup hedyphane group Pb 2+ 6s 2 lone-electron-pair Blue Bell claims California The minerals of the apatite supergroup (with the apatite structure) have...

... with andradite, hedyphane, aegirine, rhodonite, melanotekite, calcite, quartz, potassium feldspar, pectolite, and barite. It is inferred to have formed below 300 °C at 2-4 kbar from the breakdown of medium-temperature metamorphic assemblages in which hedyphane was the principal reactant. The name is from...

.... , 2010 ). Based on chemical and crystal-chemical grounds, the following five mineral groups have been distinguished within the apatite supergroup: apatite group, hedyphane group, belovite group, britholite group and ellestadite group. Among all these groups, the minerals belonging to the apatite group...

... the highest symmetry P 6 3 / m structure and this space group was used to refine the structures of our samples. F ig . 3. X-ray map of Ca, As, Pb and Cl in the johnbaumite sample. The Ca-As-rich host is partly altered to patches and veins of Pb-Cl-rich hedyphane. T able 3. Final EXAFS...

...Roland C. Rouse; Peter J. Dunn; Donald R. Peacor Abstract Hedyphane, traditionally formulated as (Ca,Pb) 5 (AsO 4 ,PO 4 ) 3 Cl, is redefined as Ca 2 Pb 3 (AsO 4 ) 3 Cl with Z = 2. The space group is P 6 3 / m with a = 10.140(3) and c = 7.185(4)Å. Observed and calculated densities are 5.85 and 5.99...

... of the Cambrian Ajax Limestone, next to a tectonic contact with the diapiric, halite-bearing clastic sediments of the Callanna Group. The orebody is associated with hematite alteration and is characterized by the total absence of sulfides; willemite is the only zinc ore mineral, and the arsenate hedyphane (Ca 2...

...Erich U. Petersen; Lawrence M. Anovitz; Eric J. Essene Abstract A Mn-rich orthopyroxene Mg 1.41 Mn 0.56 Ca 0.03 Si 2 O 6 , occurs in a manganiferous pod in the marble units near Balmat, N. Y. The pyroxene coexists with triodite, tourmaline, ferrian braunite, manganoan dolomite, and hedyphane...

... of minerals. Finally, the Hedyphane Group ( T able 1 ) is composed of phosphate, arsenate, and sulfate minerals in which the M 1 and M 2 sites are occupied by different atomic species. The group is typified by the eponymous arsenate mineral hedyphane, [Ca 2 Pb 3 (AsO 4 ) 3 Cl] in which Ca occupies...

... μm in size, in a calcite gangue, associated with cinnabar, djurleite, galena and hedyphane. Vrančiceite is black, with metallic lustre. Mohs hardness is ca . 2–3, calculated density is 6.652 g.cm –3 . In reflected light, vrančiceite is light grey with a yellowish shade; bireflectance, pleochroism...

...F ig . 11. BSEI of apatite-group eutectoid growing in hyalophane. Darker contrast in feldspar indicates a zone of Pb depletion surrounding hedyphane. ...

... + , REE 3+ , Sr 2+ ; the P atom in the phosphate group is usually replaced by other small tetrahedrally coordinated atoms such as As, V, S, or Si; and F is replaced by Cl, OH, or both. In some cases, such as hedyphane Ca 2 Pb 3 (AsO 4 ) 3 Cl or phosphohedyphane, the P 6 3 / m symmetry is maintained...