Crystal Chemistry and Structure of Kimzeyite, Ca3zr2[Al2si]

University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2018-08-21 Crystal Chemistry and Structure of kimzeyite, Ca3Zr2[Al2Si]Σ3O12, henritermierite, Ca3Mn2[(SiO4)2(O4H4)1]Σ3, (OH,F)-spessartine, Mn2+3Al2[(SiO4)2(O4H4,F4)1]Σ3, and hausmannite, Mn3O4 Cruickshank, Laura Ann Cruickshank, L. A. (2018). Crystal Chemistry and Structure of kimzeyite, Ca3Zr2[Al2Si]Σ3O12, henritermierite, Ca3Mn2[(SiO4)2(O4H4)1]Σ3, (OH,F)-spessartine, Mn2+ 3Al2[(SiO4)2(O4H4,F4)1]Σ3, and hausmannite, Mn3O4 (Unpublished master's thesis).. University of Calgary, Calgary, AB. doi:10.11575/PRISM/32836 http://hdl.handle.net/1880/107656 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY Crystal Chemistry and Structure of kimzeyite, Ca3Zr2[Al2Si]Σ3O12, henritermierite, 2+ Ca3Mn2[(SiO4)2(O4H4)1]Σ3, (OH,F)-spessartine, Mn 3Al2[(SiO4)2(O4H4,F4)1]Σ3, and hausmannite, Mn3O4 by Laura Ann Cruickshank A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN GEOLOGY AND GEOPHYSICS CALGARY, ALBERTA AUGUST, 2018 © Laura Ann Cruickshank 2018 ii ABSTRACT This study considers the crystal chemistry of some rare garnet-group minerals of the general [8] [6] [4] formula X3 Y2 Z3O12 including kimzeyite, Ca3Zr2[Al2Si]Σ3O12, henritermierite, 2+ Ca3Mn2[(SiO4)2(O4H4)1]Σ3, and (OH,F)-spessartine, Mn 3Al2[(SiO4)2(O4H4,F4)1]Σ3. Most garnets have cubic symmetry, with space group Ia3d, but a few uncommon exceptions have been reported with tetragonal symmetry, and space group I41/acd. A sample of kimzeyite, from type- locality, Magnet Cove, Arkansas, USA, a sample of henritermierite, from Wessels Mine X, Kalahari manganese field, Northern Cape Province, South Africa, and a sample of (OH,F)- bearing spessartine, from Tongbei, near Yunxiao, Fujian Province, China were studied using electron-probe microanalysis (EPMA), back-scattered electron imaging (BSE), single crystal X- ray diffraction (SCXRD) and synchrotron high-resolution powder X-ray diffraction (HRPXRD). For kimzeyite, structural Rietveld refinements confirmed cubic space group Ia3d and achieved reduced χ2 and overall R(F2) values of 1.840 and 0.0647, respectively. The kimzeyite sample contains an intergrowth of two cubic phases that began as oscillatory growth zoning, with later fluid-enhanced dissolution and re-precipitation giving rise to patchy intergrowths. For henritermierite and (OH,F)-bearing spessartine, the SCXRD structure refinements confirmed 2 tetragonal space group I41/acd, and produced a goodness of fit on F of 1.209 and 1.232 for henritermierite and (OH,F)-spessartine, respectively. In henritermierite, the deviation of unit-cell parameters from cubic symmetry is significant (a = 12.4908(2) Å, c = 11.6446(2) Å, c/a = 0.9534). Tetragonal henritermierite has a vacant Z2 site that contains the substituent O4H4 tetrahedron. The H atom is bonded to an O3 atom (O3 – H3) = 0.73(2) Å. Because of O2 – 3+ 3+ Mn – O2 Jahn-Teller elongation of the Mn O6 octahedron, a weak hydrogen bond is formed to the under-bonded O2 atom. This causes the large deviation from cubic symmetry. In (OH,F)- iii spessartine, the Z2 site is fully occupied, but the Z1 site contains vacancies. The Z1 and Z2 sites occupied by Si atoms are surrounded by four O atoms, as seen in cubic garnets. When the Z site is vacant, a larger [(O2H2)(F2)] tetrahedron is formed, and is similar to the O4H4 tetrahedron in hydrogarnets. These results indicate a new possible end-member: 2+ Mn 3Al2[(SiO4)2(O2H2)0.5(F2)0.5]Σ3, which remains unknown. Finally, this study also examines a tetragonal spinel mineral, hausmannite, ideally Mn3O4. The sample comes from the henritermierite specimen previously described, and has tetragonal space group I41/amd. The SCXRD structure refinement confirmed the tetragonal symmetry, and produced a goodness of fit 2 on F of 1.144 and R indices of R1 = 0.0277 and wR2 = 0.0559. Henritermierite and hausmannite spinel occur as an intergrowth, observed in a BSE image. Hausmannite is thought to be an original mineral from which henritermierite was formed by a reaction that includes quartz, SiO2, calcite, CaCO3, and H2O. iv ACKNOWLEDGEMENTS I would like to express sincere thanks to my supervisor, Dr. Sytle Antao, for her guidance, encouragement and support during my time at the University of Calgary, during both my undergraduate and graduate degrees. Being given the opportunity to be a member of her research group for the last three years, through my undergraduate research project and my graduate degree has contributed significantly to both my personal and professional development. Her passion for mineralogy has continually inspired me to never stop learning. I would like to thank Dr. Robert Marr for his assistance with electron-probe microanalysis throughout the course of my research, and Benjamin Gelfand, for his assistance with single crystal X-ray diffraction data collection. Inayat Dhaliwal, Melissa Greig, Han Nguyen, Joseph Ma, and Jeffrey Salvador are thanked for their valuable advice, discussions and support throughout my time at the University of Calgary. Finally, I am most grateful to my family for their unconditional love and encouragement, and would like to thank my parents for raising me to always believe that I could do whatever I wanted to do and be whoever I wanted to be. v TABLE OF CONTENTS Abstract............................................................................................................................................ii Acknowledgements.........................................................................................................................iv Table of Contents............................................................................................................................v List of Tables..................................................................................................................................vi List of Figures...............................................................................................................................viii CHAPTER 1 INTRODUCTION TO THE GARNET GROUP MINERALS.................................1 1.1 Organization of the Thesis............................................................................................2 CHAPTER 2 CRYSTAL CHEMISTRY OF KIMZEYITE............................................................4 2.1 Introduction to Kimzeyite.............................................................................................4 2.2 Sample Description and Experimental Techniques......................................................8 2.2.1 Electron-probe Microanalysis (EPMA).........................................................9 2.2.2 Synchrotron High-resolution Powder X-ray Diffraction (HRPXRD).........12 2.2.3 Rietveld Structure Refinement.....................................................................12 2.3 Results.........................................................................................................................13 2.4 Discussion...................................................................................................................22 2.5 Conclusions.................................................................................................................25 CHAPTER 3 CRYSTAL CHEMISTRY OF HENRITERMIERITE AND (OH,F)- SPESSARTINE ............................................................................................................................27 3.1 Introduction to Henritermierite and (OH,F)-bearing Spessartine...............................27 3.2 Sample Description.....................................................................................................31 3.2.1 Electron-probe Microanalysis (EPMA).......................................................31 3.2.2 Single Crystal X-ray Diffraction (SCXRD).................................................33 3.2.3 Synchrotron High-resolution Powder X-ray Diffraction (HRPXRD).........34 3.3 Results.........................................................................................................................39 3.3.1 Henritermierite.............................................................................................41 3.3.2 (OH,F)-bearing Spessartine.........................................................................47 3.4 Conclusions.................................................................................................................51 CHAPTER 4 CRYSTAL CHEMISTRY OF HAUSMANNITE..................................................52 4.1 Introduction to Hausmannite.......................................................................................52 4.2 Sample Description and Experimental Techniques....................................................54 4.2.1 Electron-probe Microanalysis (EPMA).......................................................55 4.2.2 Single Crystal X-ray Diffraction (SCXRD).................................................55 4.3 Results.........................................................................................................................56

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