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Gunterite

A valid IMA mineral species
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03629340017271951481266.jpg
Mickey E. Gunter
Formula:
Na4Ca(V10O28) · 20H2O
the original formula, Na4(H2O)16(H2V10O28)•6H2O, was revised and changed in 2021 (Newsletter #61, proposal 21-B)
Colour:
Orange-yellow
Lustre:
Sub-Adamantine
Hardness:
1
Specific Gravity:
2.398 (Calculated)
Crystal System:
Monoclinic
Name:
Named in honor of Dr. Mickey Eugene Gunter (b. 1953), Professor of Mineralogy at the University of Idaho. Professor Gunter is particularly well known for his studies in optical mineralogy and the mineralogy of asbestos minerals.
This page provides mineralogical data about Gunterite.


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Unique IdentifiersHide

Mindat ID:
42440
Long-form identifier:
mindat:1:1:42440:0

Similar NamesHide

GanteriteA valid IMA mineral speciesBa0.5(Na,K)0.5Al2(Si2.5Al1.5)O10(OH)2
GungeriteA valid IMA mineral speciesTlAs5Sb4S13
KantoriteA valid IMA mineral speciesK2NaMg(SO4)2F
KonderiteA valid IMA mineral speciesCu3Pb(Rh,Pt,Ir)8S16

Classification of GunteriteHide

00669880017683444897551.jpg
The Decavanadate Cluster

The decavanadate cluster found in gunterite. The same cluster is known in a number of other secondary vanadium minerals including, for example, rakovanite, postite, and hughesite.

IMA Classification of GunteriteHide

Approved
IMA status notes:
Redefined by the IMA
IMA Formula:
Na4Ca[V5+10O28]·20H2O
Approval year:
2011
First published:
2011
Approval history:
The original formula, Na4(H2O)16(H2V10O28)•6H2O, was revised and changed in 2021 (CNMNC Newsletter #61, proposal 21-B).
4.HC.35

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
C : [6]-Sorovanadates

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
GunIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of GunteriteHide

Sub-Adamantine
Transparency:
Transparent, Translucent
Colour:
Orange-yellow
Streak:
Yellow
Hardness:
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
none
Fracture:
Irregular/Uneven
Density:
2.398 g/cm3 (Calculated)

Optical Data of GunteriteHide

Type:
Biaxial (+)
RI values:
nα = 1.735(5) nβ = 1.770(5) nγ = 1.825(5)
2V:
Measured: 78°
Max. Birefringence:
δ = 0.090
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.

Surface Relief:
Moderate
Dispersion:
v < r, strong, parallel
Optical Extinction:
X = b, Y ≈ c.
Pleochroism:
Visible
Comments:
X = yellow; Y = orange; Z yellow.
Comments:
γ calculated (index fluids decomposed mineral)

Absorption: Y > X > Z.

Chemistry of GunteriteHide

Mindat Formula:
Na4Ca(V10O28) · 20H2O

the original formula, Na4(H2O)16(H2V10O28)•6H2O, was revised and changed in 2021 (Newsletter #61, proposal 21-B)
Element Weights:
Element% weight
O52.973 %
V35.138 %
Na6.343 %
H2.781 %
Ca2.765 %

Calculated from ideal end-member formula.

Crystallography of GunteriteHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 19.848(2) Å, b = 10.1889(11) Å, c = 13.1184(15) Å
β = 130.187(9)°
Ratio:
a:b:c = 1.948 : 1 : 1.288
Unit Cell V:
2,026.68 ų (Calculated from Unit Cell)
Z:
2

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0018627GunteriteKampf A R, Hughes J M, Marty J, Nash B (2011) Gunterite, Na4(H2O)16(H2V10O28)*6H2O, a new mineral species with a doubly-protonated decavanadate polyanion: crystal structure and descriptive mineralogy The Canadian Mineralogist 49 1243-12512011West Sunday mine, San Miguel County, Colorado, USA0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
10.01 Å(100)
8.44 Å(72)
8.09 Å(46)
2.997 Å(29)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]
47e : [Vanadates, chromates, manganates]
Stage 10b: Anthropogenic minerals<10 Ka
55 : Anthropogenic mine minerals

Type Occurrence of GunteriteHide

General Appearance of Type Material:
Tabular on {001} and generally stacked into elongate curved multiple crystals up to 0.5 mm in maximum dimension. The crystals typically exhibit warping and, in some cases, skeletal growth features.
Place of Conservation of Type Material:
Natural History Museum of Los Angeles County under catalogue numbers 63506 and 63507.
Geological Setting of Type Material:
Efflorescences on the sandstone walls of the mine workings and in fractures in the sandstone forming from the
oxidation of montroseite–corvusite assemblages.
Associated Minerals at Type Locality:

Synonyms of GunteriteHide

Other Language Names for GunteriteHide

Dutch:Gunteriet
German:Gunterit

Relationship of Gunterite to other SpeciesHide

Other Members of Pascoite Family:
Ammoniolasalite[(NH4)2Mg2(H2O)20] [V10O28]Mon. 2/m : B2/b
BluestreakiteK4Mg2(V4+2V5+8O28) · 14H2OMon. 2/m
BurroiteCa2(NH4)2(V10O28) · 15H2OTric. 1 : P1
Caseyite[(V5+O2)Al10-x(OH)20-2x(H2O)18-2x]2[H2V4+V5+9O28][V5+10O28]2(Na,K,Ca)2-y(SO4)2-z · (60+8x+y+4z)H2O (x = 0-2.5; y = 0-2; z = 0-2)Mon.
Flatimerite[Al13(OH)24(H2O)24][V5+9V4+O28] · [(SO4)4(H2O)24]Tric. 1 : P1
HuemuliteNa4Mg(V10O28) · 24H2OTric.
HughesiteNa3Al(V10O28) · 22H2OTric. 1 : P1
HummeriteK2Mg2(V10O28) · 16H2OTric. 1 : P1
HydropascoiteCa3(V10O28) · 24H2OTric. 1 : P1
KokinositeNa2Ca2(V10O28) · 24H2OTric. 1 : P1
LasaliteNa2Mg2(V10O28) · 20H2OMon. 2/m : B2/b
MagnesiopascoiteCa2Mg(V10O28) · 16H2OMon. 2/m : B2/m
NashiteNa3Ca2[(V5+9V4+)O28] · 24H2OMon. 2/m : P21/m
OkieiteMg3[V10O28] · 28H2OTric. 1 : P1
PascoiteCa2Ca(V10O28) · 17H2OMon. 2 : B2
PostiteMg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2OOrth. mmm(2/m2/m2/m) : Pccn
Protocaseyite[Al4(OH)6(H2O)12][V10O28] · 8H2OTric. 1 : P1
Rakovanite(NH4)3Na3(V10O28) · 12H2OMon. 2/m
Schindlerite{(NH4)4Na2(H2O)10}{V10O28}Tric. 1 : P1
TrebiskyiteNa3Mg2[TiV9O28] · 22H2OMon. 2/m : P21/b
Wernerbaurite{(NH4)2[Ca2(H2O)14](H2O)2}{V10O28}Tric. 1 : P1

Related Minerals - Strunz-mindat GroupingHide

4.HC.Protocaseyite[Al4(OH)6(H2O)12][V10O28] · 8H2OTric. 1 : P1
4.HC.Ammoniolasalite[(NH4)2Mg2(H2O)20] [V10O28]Mon. 2/m : B2/b
4.HC.BeckettiteCa2V6Al6O20Tric. 1 : P1
4.HC.05PascoiteCa2Ca(V10O28) · 17H2OMon. 2 : B2
4.HC.05HydropascoiteCa3(V10O28) · 24H2OTric. 1 : P1
4.HC.05LasaliteNa2Mg2(V10O28) · 20H2OMon. 2/m : B2/b
4.HC.05HughesiteNa3Al(V10O28) · 22H2OTric. 1 : P1
4.HC.05MagnesiopascoiteCa2Mg(V10O28) · 16H2OMon. 2/m : B2/m
4.HC.05Rakovanite(NH4)3Na3(V10O28) · 12H2OMon. 2/m
4.HC.10HummeriteK2Mg2(V10O28) · 16H2OTric. 1 : P1
4.HC.15SherwooditeCa5.5(AlV4+V5+12O39) · 28H2OTet. 4/mmm(4/m2/m2/m) : I41/amd
4.HC.20BluestreakiteK4Mg2(V4+2V5+8O28) · 14H2OMon. 2/m
4.HC.25Wernerbaurite{(NH4)2[Ca2(H2O)14](H2O)2}{V10O28}Tric. 1 : P1
4.HC.25BurroiteCa2(NH4)2(V10O28) · 15H2OTric. 1 : P1
4.HC.30Caseyite[(V5+O2)Al10-x(OH)20-2x(H2O)18-2x]2[H2V4+V5+9O28][V5+10O28]2(Na,K,Ca)2-y(SO4)2-z · (60+8x+y+4z)H2O (x = 0-2.5; y = 0-2; z = 0-2)Mon.
4.HC.40KokinositeNa2Ca2(V10O28) · 24H2OTric. 1 : P1
4.HC.45NashiteNa3Ca2[(V5+9V4+)O28] · 24H2OMon. 2/m : P21/m
4.HC.50OkieiteMg3[V10O28] · 28H2OTric. 1 : P1
4.HC.55PostiteMg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2OOrth. mmm(2/m2/m2/m) : Pccn
4.HC.60Schindlerite{(NH4)4Na2(H2O)10}{V10O28}Tric. 1 : P1

Fluorescence of GunteriteHide

Not fluorescent.

Other InformationHide

Notes:
Soluble in water at room temperature.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for GunteriteHide

References for GunteriteHide

Localities for GunteriteHide

Showing 3 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
USA
 
  • Colorado
    • San Miguel County
Kampf et al. (2019)
    • Slick Rock Mining District
www.handbookofmineralogy.org (2015)
Kampf et al. (2011) +1 other reference
 
and/or  
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