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

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

dc.contributor.advisor	Antao, Sytle M.
dc.contributor.author	Cruickshank, Laura Ann
dc.contributor.committeemember	Cuthbertson, Jennifer Paige
dc.contributor.committeemember	Spencer, Ronald J.
dc.date	2018-11
dc.date.accessioned	2018-08-27T14:54:28Z
dc.date.available	2018-08-27T14:54:28Z
dc.date.issued	2018-08-21
dc.description.abstract	This study considers the crystal chemistry of some rare garnet-group minerals of the general formula [8]X3[6]Y2[4]Z3O12 including kimzeyite, Ca3Zr2[Al2Si]Σ3O12, henritermierite, Ca3Mn2[(SiO4)2(O4H4)1]Σ3, and (OH,F)-spessartine, Mn2+3Al2[(SiO4)2(O4H4,F4)1]Σ3. Most garnets have cubic symmetry, with space group Ia3 ̅d, 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 Ia3 ̅d 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 tetragonal space group I41/acd, and produced a goodness of fit on F2 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 – Mn3+ – O2 Jahn-Teller elongation of the Mn3+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)-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: Mn2+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 on F2 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.	en_US
dc.identifier.citation	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 (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32836	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/32836
dc.identifier.uri	http://hdl.handle.net/1880/107656
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Science
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	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.
dc.subject	crystal chemistry
dc.subject	synchrotron high-resolution powder x-ray diffraction
dc.subject	single crystal x-ray diffraction
dc.subject	rietveld refinement
dc.subject	electron probe microanalysis
dc.subject	optical anisotropy
dc.subject	crystal symmetry
dc.subject	garnet
dc.subject	henritermierite
dc.subject	spessartine
dc.subject	kimzeyite
dc.subject	hausmannite
dc.subject.classification	Geochemistry	en_US
dc.subject.classification	Geology	en_US
dc.subject.classification	Mineralogy	en_US
dc.title	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
dc.type	master thesis
thesis.degree.discipline	Geoscience
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.item.requestcopy	true