466:
O contained within
Kegginite, it defracts relatively weakly leading to being limited to 2θ < 40°. However, a defined structure has been identified and is broken into two distinct parts, a structural unit and an interstitial complex. The structural unit is a heteropolyanion composed of 12 distorted
308:
as the basis of the structural unit. It also recognizes the work of J.F. Keggin who first experimentally described the structure of the α-Keggin anions in 1934. At the time of its discovery it represented a new crystal structure type and was the first mineral discovered with a vanadyl-containing
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Kegginite has been found in the main tunnel level of the
Packrat mine, near Gateway, Mesa County, Colorado, U.S.A. The Packrat Mine is near the northern end of the Uravan Mineral Belt. Kegginite is very rare, it has been found sparingly on only a few small samples but often in association with
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octahedra. Without the capping tetrahedron, the heteropolyanion is the ε-isomer of the Keggin anion. The formula of the interstitial unit is . The Pb site is located above each of the remaining cavities located in the mono-capped Keggin anion.
322:, with brittle tenacity, irregular fracture, and good cleavage on {001}. Due to the very limited amount of crystals available, their size, and dark color make it impossible to obtain reliable measurements of the indices of refraction.
317:
Crystals of kegginite are orange-red hexagonal tablets. The crystals are transparent vitreous and have a pinkish-orange streak. Kegginite is non-fluorescent in long wave and short wave ultraviolet light. It exhibits a 2 on the
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Anthony R. Kampf, John M. Hughes, Barbara P. Nash, and Joe Marty (2017) Kegginite, a new mineral with a novel ε-isomer of the Keggin anion. American
Mineralogist, Volume 102, pages 461-465.
304:. This specific mineral is very rare, and has only been found in one specific level of the Packrat mine. Kegginite is named as such due to the presence of the ε-isomer of the
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454:, and sherwoodite. Kegginite forms from the oxidation of montroseite-corvusite assembleges in moist environments.
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Kondinski, A., Parac-Vogt, T. N., 2018, Keggin
Structure, Quō Vādis?, Frontiers in Chemistry, v 6,
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479:(vanadate) tetrahedron, which shares three of its four vertices with the VO
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https://www.frontiersin.org/articles/10.3389/fchem.2018.00346
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475:(arsenate) tetrahedron and capped by a VO
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300:mineral discovered in Packrat mine near
280:O and soluble at room temperature in HCl
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471:octahedra surrounding a central AsO
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528:https://mindat.org/min-47606.html
313:Physical and optical properties
1:
462:Due to the high amounts of H
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309:polyoxometalate anion.
320:Mohs Scale of Hardness
150:Distinct/Good on {001}
85:Strunz classification
218:Optical properties
127:c = 15.846 Å;
576:Trigonal minerals
566:Arsenate minerals
561:Vanadate minerals
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326:Chemical analysis
302:Gateway, Colorado
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227:Refractive index
203:Pinkish - Orange
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160:Irregular/Uneven
121:a = 14.936
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44:(repeating unit)
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266:Not Fluorescent
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276:Insoluble in H
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132:Identification
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95:Crystal system
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571:Lead minerals
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446:ansermetite,
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111:3 - Pyramidal
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107:Crystal class
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390:49.01-51.30
350:26.98-29.27
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306:Keggin anion
293:
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262:fluorescence
259:Ultraviolet
249:Pleochroism
555:Categories
488:References
441:Occurrence
408:4.38-4.80
372:0.93-0.99
361:5.59-5.75
285:References
272:Solubility
176:Mohs scale
140:Orange-Red
75:IMA symbol
458:Structure
298:phosphate
294:Kegginite
239:= 2.040 n
235:= 2.035 n
213:2.69 g/cm
117:Unit cell
33:Phosphate
19:Kegginite
221:Uniaxial
193:Vitreous
179:hardness
166:Tenacity
156:Fracture
146:Cleavage
100:Trigonal
29:Category
452:mesaite
430:100.01
253:Visible
243:= 2.085
209:Density
170:Brittle
89:8.FD.10
40:Formula
24:General
448:gypsum
427:Total
420:14.59
387:47.87
347:26.82
339:Range
333:Oxide
199:Streak
189:Luster
405:4.42
369:0.92
358:5.39
296:is a
137:Color
60:* 20
366:MgO
355:CaO
344:PbO
336:wt%
79:Kgn
557::
534:^
520:^
496:^
467:VO
450:,
417:O
395:As
125:,
55:Ca
49:Pb
481:6
477:4
473:4
469:6
464:2
415:2
413:H
401:5
399:O
397:2
383:5
381:O
379:2
377:V
278:2
241:γ
237:β
233:α
231:n
183:2
123:Å
68:O
65:2
62:H
58:3
52:3
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