Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
The Canadian Mineralogist Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
The Canadian Mineralogist; October 1996; v. 34; no. 5; p. 1071-1088
© 1996 Mineralogical Association of Canada
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Finch, R. J.
Right arrow Articles by Ewing, R. C.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

The crystal structure of schoepite, [(UO 2 ) 8 O 2 (OH) 12 ](H 2 O) 12

Robert J. Finch, Mark A. Cooper, Frank C. Hawthorne, and Rodney C. Ewing

University of Manitoba, Department of Geological Sciences, Winnipeg, MB, Canada

Schoepite, [(UO 2 ) 8 O 2 (OH) 12 ](H 2 O) 12 , is orthorhombic, a 14.337(3), b 16.813(5), c 14.731(4) Aa, V 3551(2) Aa 3 , space group P2 1 ca, Z = 4. The structure has been solved by direct methods and refined on F 2 o to a weighted R index of 5.8% based on 4534 unique reflections measured with MoKalpha X-radiation on a single-crystal diffractometer (equivalent to an R index of 2.7% for F o >4sigma F o ). The refinement indicates that the formula contains eight more H 2 O groups per unit cell than previously assumed. The structure consists of neutral [(UO 2 ) 8 O 2 (OH) 12 ] sheets of edge-and corner-sharing Uphi 7 pentagonal dipyramids (phi : O, OH), hydrogen-bonded to each other through interstitial H 2 O groups. These sheets are topologically identical to those found in fourmarierite. The [(UO 2 ) 8 O 2 (OH) 12 ] sheets are interleaved with almost planar sheets of interlayer H 2 O groups. There are twelve symmetrically distinct H 2 O groups in the interlayer sheet; these are arranged in two pentagonal rings with two linking H 2 O groups. H-atom positions were not resolved, but an H-bonding scheme is suggested on the basis of stereochemical and bond-valence arguments. The structure displays strong Pbca pseudosymmetry, especially among the U atoms. The lower symmetry is primarily due to H-bond interactions between interlayer H 2 O groups and O(uranyl) atoms of the structural sheet.

This record provided courtesy of AGI/GeoRef.




This article has been cited by other articles:


Home page
 Can MineralHome page
M. Schindler and F. C. Hawthorne
THE STEREOCHEMISTRY AND CHEMICAL COMPOSITION OF INTERSTITIAL COMPLEXES IN URANYL-OXYSALT MINERALS
Can Mineral, April 1, 2008; 46(2): 467 - 501.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler, F. C. Hawthorne, P. C. Burns, and P. A. Maurice
DISSOLUTION OF URANYL-OXIDE-HYDROXY-HYDRATE MINERALS. IV. FOURMARIERITE AND SYNTHETIC Pb2(H2O)[(UO2)10UO12(OH)6(H2O)2]
Can Mineral, August 1, 2007; 45(4): 963 - 981.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
F. C. Hawthorne, R. J. Finch, and R. C. Ewing
THE CRYSTAL STRUCTURE OF DEHYDRATED WYARTITE, Ca (CO3) [U5+ (U6+O2)2 O4 (OH)] (H2O)3
Can Mineral, December 1, 2006; 44(6): 1379 - 1385.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
R. J. Finch, R. J. Finch, P. C. Burns, F. C. Hawthorne, and R. C. Ewing
REFINEMENT OF THE CRYSTAL STRUCTURE OF BILLIETITE, Ba [(UO2)6 O4 (OH)6] (H2O)8
Can Mineral, October 1, 2006; 44(5): 1197 - 1205.
[Abstract] [Full Text] [PDF]

Home page
 Mineral MagHome page
R. L. Frost, M. L. Weier, G. A. Ayoko, W. Martens, and J. Cejka
An XRD, SEM and TG study of a uranopilite from Australia
Mineralogical Magazine, June 1, 2006; 70(3): 299 - 307.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
P. C. Burns
U6+ MINERALS AND INORGANIC COMPOUNDS: INSIGHTS INTO AN EXPANDED STRUCTURAL HIERARCHY OF CRYSTAL STRUCTURES
Can Mineral, December 1, 2005; 43(6): 1839 - 1894.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler and F. C. Hawthorne
A BOND-VALENCE APPROACH TO THE URANYL-OXIDE HYDROXY-HYDRATE MINERALS: CHEMICAL COMPOSITION AND OCCURRENCE
Can Mineral, December 1, 2004; 42(6): 1601 - 1627.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler, A. Mutter, F. C. Hawthorne, and A. Putnis
PREDICTION OF CRYSTAL MORPHOLOGY OF COMPLEX URANYL-SHEET MINERALS. I. THEORY
Can Mineral, December 1, 2004; 42(6): 1629 - 1649.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler, A. Mutter, F. C. Hawthorne, and A. Putnis
PREDICTION OF CRYSTAL MORPHOLOGY OF COMPLEX URANYL-SHEET MINERALS. II. OBSERVATIONS
Can Mineral, December 1, 2004; 42(6): 1651 - 1666.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler and A. Putnis
CRYSTAL GROWTH OF SCHOEPITE ON THE (104) SURFACE OF CALCITE
Can Mineral, December 1, 2004; 42(6): 1667 - 1681.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. Schindler, F. C. Hawthorne, C. Putnis, and A. Putnis
GROWTH OF URANYL-HYDROXY-HYDRATE AND URANYL-CARBONATE MINERALS ON THE (104) SURFACE OF CALCITE
Can Mineral, December 1, 2004; 42(6): 1683 - 1697.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
K.-A. Hughes, P. C. Burns, and U. Kolitsch
THE CRYSTAL STRUCTURE AND CRYSTAL CHEMISTRY OF URANOSPHAERITE, Bi(UO2)O2OH
Can Mineral, June 1, 2003; 41(3): 677 - 685.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
M. A. Cooper and F. C. Hawthorne
BOLEITE: RESOLUTION OF THE FORMULA, K Pb26 Ag9 Cu24 Cl62 (OH)48
Can Mineral, August 1, 2000; 38(4): 801 - 808.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
S. V. Krivovichev and P. C. Burns
CRYSTAL CHEMISTRY OF URANYL MOLYBDATES. I. THE STRUCTURE AND FORMULA OF UMOHOITE
Can Mineral, June 1, 2000; 38(3): 717 - 726.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
Y. Li and P. C. Burns
INVESTIGATIONS OF CRYSTAL-CHEMICAL VARIABILITY IN LEAD URANYL OXIDE HYDRATES. II. FOURMARIERITE
Can Mineral, June 1, 2000; 38(3): 737 - 749.
[Abstract] [Full Text] [PDF]

Home page
 Can MineralHome page
P. C. Burns and F. C. Hill
A NEW URANYL SHEET IN K5[(UO2)10O8(OH)9](H2O): NEW INSIGHT INTO SHEET ANION-TOPOLOGIES
Can Mineral, February 1, 2000; 38(1): 163 - 173.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Mineralogical Association of Canada