...John M. Hughes; Anthony R. Kampf; Barbara P. Nash; Joe Marty Abstract Sherwoodite, putatively Ca 4.5 (AlV 5+ 12 V 4+ 2 O 40 )·28H 2 O, was among the early naturally occurring polyoxometalates to be reported from the Uravan Mineral Belt; the ideal formula of sherwoodite is here redefined as Ca 5.5...

...H. T. Evans; J. A. Konnert Abstract The crystal structure of sherwoodite (tetragonal, space group I 4 1 / amd; a = 28.06, c = 13.56A) has been determined from 848 counter-measured intensity data (Mo K α radiation). Difficulties with disorder and variability of crystal water as well as poor crystal...

...Mary E. Thompson; Carl H. Roach; Robert Meyrowitz Abstract Sherwoodite, a new vanadium mineral that has the probable formula Ca 3 V 8 O 22 · 15H 2 O, has been found in small amounts in many vanadium-uranium mines on the Colorado Plateau. The new mineral occurs as dark blue-black holohedral...

... sandstone. Other secondary minerals found in close association with kegginite are ansermetite, gypsum, mesaite, and sherwoodite. Crystals of kegginite are orange-red simple hexagonal tablets. The streak is pinkish-orange, the luster is vitreous, the Mohs hardness is about 2, the tenacity is brittle...

... occurs as blades on a corvusite-montroseite-bearing sandstone block intimately associated with calcite, gypsum, huemulite, pascoite, rossite, and sherwoodite. Nashite is bluish-green, with a light bluish-green streak. The mineral is transparent, with a subadamantine luster. Nashite does not fluoresce...

...). (d) The [V 10 O 28 ] 6− group in pascoite, with ten condensed (VO 6 ) polyhedra. (e) The [V 2 4+ V 5+ 12 O 40 ] group in the structures of sherwoodite and K 7 (AsV 14 O 40 (H 2 O) 12 . In (a), (b) and (d), the V atoms are indicated by large white circles. ...

.... Polyoxometalate minerals are not common, particularly outside of the Colorado Plateau. Besides the decavanadate minerals, noted above, the Colorado Plateau post-mining secondary mineral assemblages have yielded an interesting diversity of polyoxometalate minerals. Sherwoodite ( Evans & Konnert 1978 ) contains...

... common among these are minerals containing the decavanadate [V 10 O 28 ] 6– isopolyanion, and its protonated and mixed-valence variants ( Kampf et al. 2018 ). Sherwoodite, from the Peanut mine in Montrose County, Colorado ( Thompson et al. 1958 ), was the first mineral confirmed to contain...

... for electron microprobe analyses of new minerals from the Colorado Plateau. Over the past several years, numerous new minerals have been described from the mines of the Colorado Plateau. In addition to the previously described Colorado Plateau mineral sherwoodite ( Evans and Konnert 1978...

... Lindqvist anion, [Nb 6 O 19 ] 6– , is found in the minerals peterandresenite, melcherite and hansesmarkite ( cf . Friis et al. , 2017 ). Heteropolyanions in mineral structures are more structurally complex and diverse and include the heteropolyvanadate [AlV 4+ 2 V 5+ 12 O 40 ] 9– in sherwoodite ( Evans...

... ). The other POV minerals (followed by their POV clusters in parentheses) are sherwoodite [Al V 2 4 + V 12 5 + O 40 ] 9– ( Evans and Konnert 1978 ), the five members of the vanarsite family [( V x 4 + V 10 − x 5 + )O 28 ] (6+x)– ( Kampf et al. 2016...

... . 2011b ), hewettite, munirite, natrozippeite, pyrite, rakovanite ( Kampf et al . 2011a ), sherwoodite, and tyuyamunite. The optical properties of wernerbaurite and schindlerite were determined in white light. Wernerbaurite is biaxial (−). The indices of refraction are α = 1.745(3), β = 1.780(3...