The Crystal Structure of Malhmoodite from Custer, South Dakota, USA
- 19 April 2022
- journal article
- research article
- Published by Mineralogical Association of Canada in The Canadian Mineralogist
- Vol. 60 (3), 485-492
- https://doi.org/10.3749/canmin.2100029
Abstract
An occurrence of malhmoodite, Fe2+Zr(PO4)2·4H2O, from the Scott's Rose Quartz mine, Custer County, South Dakota, USA, has been identified. It occurs as divergent groups of yellowish, flat-lying platy crystals on football-size masses of altered löllingite with scorodite, parasymplesite, karibibite, schneiderhöhnite, kahlerite, and zircon. An electron probe microanalysis of malhmoodite yielded an empirical formula (based on 12 O apfu) of Fe1.06(Zr1.10Hf0.03)Σ1.13[(P0.93As0.01)Σ0.94O4]2·4H2O. Single-crystal X-ray structure analysis shows that malhmoodite is the Fe-analogue of zigrasite, MgZr(PO4)2·4H2O. Malhmoodite is triclinic with space group P and unit-cell parameters a = 5.31200(10), b = 9.3419(3), c = 9.7062(3) Å, α = 97.6111(13), β = 91.9796(11), γ = 90.3628(12)°, V = 477.10(2) Å3, Z = 2, in contrast to the previously reported monoclinic symmetry with space group P21/c and unit-cell parameters a = 9.12(2), b = 5.42(1), c = 19.17(2) Å, β = 94.8(1)°, V = 944.26 Å3, Z = 4. The crystal structure of malhmoodite is characterized by sheets composed of ZrO6 octahedra sharing all vertices with PO4 tetrahedra. These sheets are parallel to (001) and are joined together by the FeO2(H2O)4 octahedra. The structure determination of malhmoodite, along with that of zigrasite, warrants a re-investigation of synthetic compounds M2+Zr(PO4)2·4H2O (M = Mn, Ni, Co, Cu, or Zn) that have been assumed previously to be monoclinic.Keywords
This publication has 9 references indexed in Scilit:
- Natural Magnesium Hydrous Orthophosphates Bobierrite and Kovdorskite: FTIR, Raman, Thermal, and Thermochemical StudyGeochemistry International, 2020
- Preparation and Microwave Absorption Properties of Coil-like MZr(PO4)2·4H2O (M = Co2+, Ni2+, and Cu2+) MicrospheresJournal of Superconductivity and Novel Magnetism, 2019
- Raman spectroscopy of various phosphate minerals and occurrence of tuite in the Elga IIE iron meteoriteJournal of Raman Spectroscopy, 2017
- Crystal structure refinement withSHELXLActa Crystallographica Section C Structural Chemistry, 2015
- The crystal structure of zigrasite, MgZr(PO4)2(H2O)4, a heteropolyhedral framework structureMineralogical Magazine, 2010
- Zigrasite, MgZr(PO4)2(H2O)4, a new phosphate mineral from the Dunton Quarry, Newry, Oxford County, Maine, USAMineralogical Magazine, 2009
- A short history of SHELXActa Crystallographica Section A Foundations of Crystallography, 2007
- Thermal behavior of zinc γ-zirconium phosphate intercalation compoundsJournal of Thermal Analysis and Calorimetry, 2005
- The crystal structure of wycheproofite, NaAlZr(PO4)2(OH)2 H2OEuropean Journal of Mineralogy, 2004