Paramontroseite

Paramontroseite (V⁴⁺O₂) is a relatively rare orthorhombic vanadium oxide mineral in the Ramsdellite group. Synthetic paramontroseite may have applications in medicine, batteries and electronics.

Paramontroseite
Outstanding pale brown sharp crystals of the rare mineral paramontroseite, a simple vanadium oxide, from the type locality (Bitter Creek Mine, Long Park, Montrose County, Colorado, United States of America), on a contrasting dark matrix.
General
Category	Oxide minerals
Formula (repeating unit)	VO2
Strunz classification	4.DB.15a
Dana classification	4.4.11.1
Crystal system	Orthorhombic
Unit cell	a=4.905 b=9.422 c=2.916
Identification
Color	Black to grayish black
Luster	Submetallic
Streak	Black

Name

The name Paramontroseite is derived from the Greek παρα (para), meaning near, and montroseite, a related mineral.[1] The name was chosen due to the mineral's paramorphic relationship to the host mineral montroseite.[2] Montroseite is named after Montrose County, Colorado, USA, where it was first found.[3][lower-alpha 1] Names in other languages include Paramontroseit (German), Paramontroseita (Spanish), Парамонтрозеит (Russian) and 副黑钒矿 副黑铁钒矿 (Chinese).[6] Synonyms are Inorganic Crystal Structure Database (ICSD) 22303 and Powder Diffraction File (PDF) 25-1003.[1]

Occurrence

Paramontroseite is associated with montroseite and corvusite. It is found in relatively unoxidized Colorado Plateau-type uranium–vanadium ores in sandstones.[7] The type locality is Bitter Creek Mine, Paradox Valley, Uravan District, Montrose County, Colorado, USA.[8] In the USA it is found in Montrose County, Colorado, San Miguel County, Colorado, Mesa County, Colorado, Emery County, Utah, Apache County, Arizona, McKinley County, New Mexico and Fall River County, South Dakota.[9] It has also been reported from locations in the Czech Republic, Mendoza Province, Argentina and the Mounana uranium mine near Franceville, Gabon.[9]

Paramontrosite has also been found in an outcrop on the Van Irvine Ranch in the Pumpkin Buttes area of Wyoming, USA, associated with sulfides in red sandstone.[10] It is found in a zone where the sandstone changes color from red to gray. The black paramontroseite cements grains of sand into nodular masses that enclose smaller pyrite masses.[11] The irregular concretionary masses are up to 1 foot (0.30 m) across.[12] Vanadium salts have given a greenish coating to the exposed surfaces of these masses. The masses are anomalously radioactive and the surrounding sandstone is weakly radioactive. The radioactivity is mostly caused by tiny specks of coffinite in the paramontroseite.[11] When a section is polished the paramontroseite completely fills the gaps between the grains of sand. It is very soft and has a gray color that is slightly lighter than quartz gray. There is strong anisotrophism and many bright multi-colored internal reflections.[12]

Deposits of montroseite (V,Fe)OOH and paramontroseite VO₂ have been found in the Saltwash Sandstone Member of the Upper Jurassic Morrison Formation in the Colorado Plateau. From the diffraction characteristics of the paramontroseite there seem to be two distinct generations: a primary paramontroseite with good crystalline structure and a product of montroseite oxidation with poor crystalline structure.[13] The paramontroseite found in this region is among the neutral minerals in the mid-range of vanadium valence (+4) above the primary ore of montroseite (+3) but below minerals such as carnotite (+5) and pascoite (+5).[14]

Lifecycle

Paramontroseite is a metastable form of vanadium dioxide (VO₂) that results from oxidation of montroseite.[15] It is formed by dehydrogenation of montroseite.[7] Paramontroseite seems to be the most common initial product of oxidation of montroseite.[16] The primary difference between the crystal structures of the two minerals is that the oxygen–oxygen distance increases from 2.63Å in montroseite to 3.87Å in paramontroseite due to the loss of hydrogen in the latter.[15] The vanadium–oxygen distances are also somewhat shorter in paramontroseite than in montroseite, as would be expected when the vanadium is oxidized from +3 to +4 when the hydrogen is removed.[17]

The montroseite, VO(OH), is deposited in crystalline masses in a sandstone matrix by some unknown process. Usually iron occurs in place of some of the vanadium. Oxygen in the air or groundwater then oxidizes the crystallised montroseite at temperatures under 50 °C through the reaction:

2VO(OH) + ​¹⁄₂O₂ → 2VO₂ + H₂O

During the solid state alteration process the hydrogen atoms migrate through the crystal structure to the surface, where they combine with oxygen. In the process there is a slight shift in the crystal structure, but the structure remains intact.[18] The vanadium-oxygen bonds have not been broken and the hexagonal close-packed oxygen framework has not been disrupted.[19] In some cases there may be an intermediate "diffuse A" phase.[18] The process by which montroseite is altered to paramontroseite seems analogous to the magnetite → maghemite, lepidocrocite → maghemite, and goethite → hematite processes.[20]

Paramontroseite is not stable and is destroyed by weathering, replaced by minerals of the corvusite type.[18] The paramontroseite reacts under neutral or acid conditions to form many compounds such as vanadyl vanadate and metal vanadates such as hewettite, hummerite, pascoite and rossite.[21] Paramontroseite may dissolve in slightly alkaline conditions, then combine with Ca⁺⁺ to form simplotite:[22]

4VO₂ + 2OH⁻ + Ca⁺⁺ → CaV₄O₉ + H₂O

Possible applications

Autophagy is a process of cellular degradation that is essential in preserving homeostasis of cells. It is often thought that when autophagosomes encapsulate and trap inorganic nanoparticles they may be unable to degrade them and the cell's well-being may be threatened. However, experiments have shown that nanocrystals of paramontroseite induce cyto-protective autophagy in cultured HeLa cells. It is possible that this may have value in therapies.[23]

Montroseite and paramontroseite microspheres have been synthesized by hydrothermal carbonization of sucrose and calcinated to form V₂O₃-VO₂-C core-shell microspheres. These have been used experimentally as cathode materials for a lithium-ion battery.[24] Y. Xu and colleagues of the University of Science and Technology of China have shown that synthetic montroseite VOOH hollow structures can convert topochemically to paramontroseite without altering the size and appearance of the structures. Both forms appears to have potential in lithium ion batteries as anode materials.[25]

Monoclinic vanadium dioxide VO₂(M) is potentially of great value for applications such as intelligent temperature sensors and smart windows. The classic solid state transformation from vanadium precursors to rutile VO₂(R) is slow and costly. A transformation from goethite VOOH to synthetic "paramontroseite" VO₂ to the desired monoclinic VO₂(M) promises to greatly reduce cost and time.[26]

Classification

Paramontroseite was first described before 1959. It is a member of the Ramsdellite Group.[27] It is classified as follows:[28]

• Strunz 8th edition: 4/F.08-30.
• Nickel-Strunz 10th edition: 4.DB.15a
• Dana 8th edition: 4.4.11.1
• Hey's CIM Reference: 7.12.3

Properties

Physical

Physical properties of Paramontroseite include

Empirical formula	V^4+O2[1]
Chemical formula	VO2[1]
Molecular mass	82.94 gm (61.42% vanadium and 38.58% oxygen by weight).[1]
Hardness	soft[29]
Fracture	brittle[30]
Cleavage	good [30]
Density (g/cm³)	4 (measured), 4.095 (calculated)[31]
Calculated electron density	3.85 gm/cc[32]
Calculated fermion index	0.0017206735[32]
Calculated boson index	0.9982793265[32]
Radioactive	no[32][lower-alpha 2]

Chemistry

The X-ray powder diffraction pattern for a Bitter Creek mine sample is 3.39 (100), 2.645 (50), 4.35 (35), 2.213 (35), 1.426 (35), 2.479 (25), 2.179 (25). In this sample the chemistry was:[34]

V2O4	72.5
V2O3	10.5
FeO	8.8
H2O	5.0

A sample from Matchless mine, Colorado, USA had chemistry:[35]

V2O4	66.9
SiO2	6.12
Al2O3	3.00
V2O3	11.10
FeO	8.26
H2O	4.82

The measured chemistry of a microprobe fragment in the gray phase by the RRUFF project gave metals in the ratio: V⁴⁺ (82%), Fe³⁺ (9%), U⁶⁺ (4%) and Al (2%), with one metal atom per two oxygen atoms. The lightest phase was uranophane.[33]

Optical

Paramontroseite is opaque and black to grayish black in color.[36][lower-alpha 3] Its optical class is biaxial.[36] It has a sub-metallic luster and a black streak. From the Gladstone–Dale relation (KC = 0.393), the NCalc is 2.61 where Ncalc=Dcalc*KC+1, or 2.57 where Ncalc=Dmeas*KC+1.[38]

Crystallography

Paramontroseite crystal properties include:

Crystal structure	orthorhombic - dipyramidal [39]
Cell dimensions	a = 4.905Å, b = 9.422Å, c = 2.916Å, Z = 4; V = 134.76 Den (Calc) = 4.09.[39]
Ratio:a:b:c	0.5205:1:0.3094.[39]
Point group	2/m 2/m 2/m.[40]
Space group	Pbnm[41]
Space group number	62.[41]
X-Ray diffraction by intensity (I/Io)	3.39(1), 2.649(0.5), 4.35(0.35).[39]

Endmatter

Notes

1. Montrose County takes its name from the county seat, Montrose, which is named after the historical novel by Sir Walter Scott, A Legend of Montrose.[4] Montrose, in Forfarshire, Scotland, is a corruption of the Gailic monadh-rois, meaning the hill of the ravine.[5]
2. The RRUFF database shows Paramontroseite as radioactive.[33]
3. Some sources simply give the color as "black".[30][37]

Citations

1. Barthelmy, General Paramontroseite Information.
2. Evans & Mrose 1955, p. 862.
3. Barthelmy (b).
4. Heim 2007, p. 165.
5. Smythe Palmer 1882, p. 545.
6. Paramontroseite – Mindat, Other Language Names.
7. Paramontroseite – Handbook of Mineralogy, Occurrence.
8. Paramontroseite – Mindat, Type Occurrence.
9. Paramontroseite – Handbook of Mineralogy, Distribution.
10. Sharp et al. 1949, p. 605.
11. Sharp et al. 1949, p. 606.
12. Sharp et al. 1949, p. 575.
13. Wanty, Fitzpatrick & Goldhaber 1986, p. 72.
14. Wanty, Fitzpatrick & Goldhaber 1986, p. 20.
15. Evans & Mrose 1955, p. 861.
16. Garrels & Pommer 1987, pp. 158−159.
17. Evans & Mrose 1955, pp. 870–872.
18. Evans & Mrose 1955, p. 872.
19. Evans 1987, p. 94.
20. Evans & Mrose 1955, p. 874.
21. Garrels & Pommer 1987, p. 159.
22. Garrels & Pommer 1987, p. 158.
23. Zhou et al. 2013.
24. Hailong et al. 2011, p. 2049.
25. Xu 2012, p. 1815.
26. Changzheng et al. 2011, p. 791.
27. Paramontroseite – Mindat, Relationship ... to other Species.
28. Paramontroseite – Mindat, Classification.
29. Paramontroseite – Handbook of Mineralogy, Physical Properties.
30. Barthelmy, Physical Properties.
31. Schorn, Physikalische Eigenschaften.
32. Barthelmy, Calculated Properties.
33. Armbruster & Danisi.
34. Paramontroseite – Handbook of Mineralogy, X-ray Powder Pattern.
35. Paramontroseite – Handbook of Mineralogy, Chemistry.
36. Paramontroseite – Handbook of Mineralogy, Optical Properties.
37. Paramontroseite – Mindat.
38. Barthelmy, Optical Properties.
39. Barthelmy, Paramontroseite Crystallography.
40. Paramontroseite – Handbook of Mineralogy, Crystal Data.
41. Schorn, Kristallographie.

Sources

• Armbruster, Thomas; Danisi, Rosa Micaela (eds.), "Paramontroseite R050391", RRUFF database, retrieved 2018-03-20
• Barthelmy, Dave, "Paramontroseite Mineral Data", webmineral.com, retrieved 2018-03-20
• Barthelmy (b), David, "Montroseite Mineral Data", webmineral.com, retrieved 2018-03-20
• Changzheng, Wu; Feng, Feng; Jun, Feng; Jun, Dai; Jinlong, Yang; Yi, Xie (2011), "Ultrafast Solid-State Transformation Pathway from New-Phased Goethite VOOH to Paramontroseite VO2 to Rutile VO2(R)", J. Phys. Chem. C, 115 (3): 791–799, doi:10.1021/jp109967j
• Evans, Howard T., Jr. (1987), "The Crystal Chemistry and Mineralogy of Vanadium", Geological Survey professional paper, Govt. Print. Off., retrieved 2018-03-20
• Evans, Howard T., Jr.; Mrose, Mary E. (1955), "A crystal Chemical Study of Montroseite and Paramontroseite" (PDF), American Mineralogist, 40, retrieved 2018-03-20
• Hailong, Fei; Xiaokun, Ding; Mingdeng, Wei; Kemei, Wei (November 2011), "Facile synthesis of Montroseite VOOH, Paramontroseite VO2 and V2O3-VO2 carbonaceous core-shell microspheres", Solid State Sciences, 13 (11), doi:10.1016/j.solidstatesciences.2011.09.009
• Garrels, R. M.; Pommer, A. M. (1987), "Some Quantitative Aspects of the Oxidation and Reduction of the Ores", Geological Survey professional paper, Govt. Print. Off., retrieved 2018-03-20
• Heim, Michael (2007), Exploring Colorado Highways: Trip Trivia, Exploring America's Highway, ISBN 978-0-9777301-0-0, retrieved 2018-03-20
• "Paramontroseite" (PDF), Handbook of Mineralogy, Mineral Data Publishing, retrieved 2018-03-15
• "Paramontroseite", Mindat.org, Hudson Institute of Mineralogy, retrieved 2018-03-15
• Schorn, Stefan, "Paramontroseit", Mineralienatlas - Fossilienatlas (in German), retrieved 2018-03-20
• Sharp, W.N.; McKay, E.J.; McKeown, F.A.; White, A.M. (1949), "Geology and Uranium Deposits of the Pumpkin Buttes Area of the Powder River Basin, Wyomong", Geological Survey Bulletin, U.S. Department of the Interior, Geological Survey; Washington, D.C., retrieved 2018-03-20
• Smythe Palmer, A. (1882), Folk-Etymology, Ardent Media, GGKEY:NS8KWYGW93Y, retrieved 2018-03-20
• Wanty, Richard B.; Fitzpatrick, Joan J.; Goldhaber, Martin B. (1986), "Geochemical and Crystallographic Constrains on the Formation of the Vanadium-Uranium Ores of the Colorado Plateau", The Georges Bank Monitoring Program 1985: Analysis of Trace Metals in Bottom Sediments During the Third Year of Monitoring, The US Geological Survey
• Xu, Y. (2012-01-09), "From synthetic montroseite VOOH to topochemical paramontroseite VO2 and their applications in aqueous lithium ion batteries", Issues in Chemistry and General Chemical Research: 2011 Edition, ScholarlyEditions, ISBN 978-1-4649-6334-6
• Zhou, W; Miao, Y; Zhang, Y; Liu, L; Lin, J; Yang, JY; Xie, Y; Wen, L. (26 April 2013), "Induction of cyto-protective autophagy by paramontroseite VO2 nanocrystals", Nanotechnology, 24 (16): 165102, doi:10.1088/0957-4484/24/16/165102, PMID 23535229