Pseudodickthomssenite, Mg(VO₃)₂·8H₂O, a New Mineral from the Pickett Corral Mine, Bull Canyon, Montrose County, Colorado, USA
Abstract
Pseudodickthomssenite (IMA2021-027), Mg(VO₃)₂·8H₂O, is a new mineral discovered at the Pickett Corral mine, Bull Canyon, Montrose County, Colorado, USA. The mineral formed from the oxidation of montroseite-corvusite assemblages in a moist environment and occurs on asphaltite and on montroseite-corvusite-bearing sandstone in association with dickthomssenite, gypsum, huemulite, lasalite, and trebiskyite. Pseudodickthomssenite is known only from a diverging cluster of striated needles up to about 500 μm long and 20 μm in diameter; the mineral is light tan in color, with a white streak and a silky luster. The crystals are brittle but somewhat flexible in thin fibers. There are two excellent cleavages, {011} and {011̅}, and the fracture is splintery. The measured density is 1.97(2) g/cm³. Electron probe microanalysis provided the empirical formula [Mg_(0.99)Ca_(0.01)]_(Σ1.00)(V⁵⁺O₃)₂·8H₂O. Pseudodickthomssenite is triclinic, P1̅, a = 7.3566(6) Å, b = 9.4672(9) Å, c = 9.5529(9) Å, α = 104.205(7)°, β = 100.786(7)°, γ = 100.157(7)°, V = 616.08(10) ų, and Z = 2. The structure of pseudodickthomssenite (R₁ = 0.0307 for 1124 I > 2σI reflections) contains V⁵⁺O₅ polyhedra that link by edge-sharing to form a zig-zag [VO₃] chain. MgO₂(H₂O)₄ octahedra link the [VO₃] chains into a Mg(H₂O)₄[VO₃]₄ sheet and the sheets are linked to one another via a complex network of hydrogen bonding involving Mg(H₂O)₆ octahedra and isolated H2O groups. The structure is very similar to that of dickthomssenite.
Additional Information
Reviews by Associate Editor Emanuela Schingaro and two anonymous reviewers improved the manuscript. This study was funded, in part, by the John Jago Trelawney Endowment to the Mineral Sciences Department of the Natural History Museum of Los Angeles County.Additional details
- Alternative title
- Pseudodickthomssenite, Mg(VO3)2·8H2O, a New Mineral from the Pickett Corral Mine, Bull Canyon, Montrose County, Colorado, USA
- Eprint ID
- 118070
- Resolver ID
- CaltechAUTHORS:20221128-494241100.31
- John Jago Trelawney Endowment
- Created
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2022-12-17Created from EPrint's datestamp field
- Updated
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2022-12-17Created from EPrint's last_modified field