Bokite
A valid IMA mineral species
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About Bokite
Ivan I. Bok
Formula:
(Al,Fe)1.3(V5+,V4+,Fe3+)8O20 · 7.5H2O
Colour:
Black
Lustre:
Sub-Metallic, Dull
Hardness:
3
Specific Gravity:
2.97 - 3.1
Crystal System:
Monoclinic
Member of:
Name:
Named in 1963 by E.A. Ankinovich in honor of Ivan Ivanovich Bok (Иван Иванович Бок) (10 October 1898, Belebey, Bashkortostan, Russian Empire - 30 September 1983, Leningrad, USSR), geologist, Institute of Geosciences, Alma-Ata, Kazakhstan and instructor, Sverdlovsk Mining Institute (then Kazakhstan Mining and Metallurgical Institute).
Unique Identifiers
Mindat ID:
709
Long-form identifier:
mindat:1:1:709:0
Similar Names
| Backite | A valid IMA mineral species | Pb2AlTeO6Cl |
| Beekite | A variety of 'Chalcedony' [Quartz] | SiO2 |
| Boiite | A synonym of 'Hornblende-gabbro' |
IMA Classification of Bokite
Approved
IMA Formula:
(Al,Fe3+)1.3(V5+,V4+,Fe3+)8O20·7.5H2O
First published:
1963
Classification of Bokite
4.HE.20
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
E : Phyllovanadates
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
E : Phyllovanadates
47.3.2.5
47 : VANADIUM OXYSALTS
3 : Hydrated Normal Vanadium Oxysalts
47 : VANADIUM OXYSALTS
3 : Hydrated Normal Vanadium Oxysalts
21.4.25
21 : Vanadates (and vanadates with arsenate or phosphate)
4 : Vanadates of U, Mn, Fe or Ni
21 : Vanadates (and vanadates with arsenate or phosphate)
4 : Vanadates of U, Mn, Fe or Ni
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Bkt | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Bokite
Sub-Metallic, Dull
Transparency:
Opaque
Colour:
Black
Streak:
Black, may be brownish black
Hardness:
3 on Mohs scale
Cleavage:
Perfect
parallel to elongation; fair, perpendicular to first direction
parallel to elongation; fair, perpendicular to first direction
Density:
2.97 - 3.1 g/cm3 (Measured) 3.41 g/cm3 (Calculated)
Optical Data of Bokite
Type:
Biaxial
RI values:
nα = 2.01 nγ = 2.06
Max. Birefringence:
δ = 0.050
Based on recorded range of RI values above.
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.
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:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Anisotropism:
Strong, brownish yellow to grey-blue
Dispersion:
Relatively weak
Colour in reflected light:
Light grey
Pleochroism:
Strong
Comments:
Dirty olive-green to deep reddish brown
Chemistry of Bokite
Mindat Formula:
(Al,Fe)1.3(V5+,V4+,Fe3+)8O20 · 7.5H2O
Element Weights:
Crystallography of Bokite
Crystal System:
Monoclinic
Cell Parameters:
a = 11.838(5) Å, b = 3.643(1) Å, c = 11.142(5) Å
β = 110.58(4)°
β = 110.58(4)°
Ratio:
a:b:c = 3.25 : 1 : 3.058
Unit Cell V:
449.84 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Platy to columnar or wedge-shaped grains, to 0.3 mm; reniform crusts with radiating structure; also in veinlets.
Comment:
Point Group: n.d.; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.47 Å | (100) |
| 3.452 Å | (30) |
| 2.907 Å | (12) |
| 2.592 Å | (12) |
| 1.8208 Å | (11) |
| 3.177 Å | (9) |
| 2.760 Å | (9) |
Comments:
Recorded on material from the Kurumsak deposit, Kazakhstan
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Geological Setting:
As a constituent of U-V ores in triassic stream channels and impregnating sandstone
Type Occurrence of Bokite
Co-Type Localities:
General Appearance of Type Material:
Platy to columnar or wedge-shaped grains, to 0.3 mm long,
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA (No. 139767)
Geological Setting of Type Material:
In carbonaceous vanadiferous shales
Associated Minerals at Type Locality:
Other Language Names for Bokite
Relationship of Bokite to other Species
Member of:
Other Members of Straczekite Group:
| Bariandite | Al0.6(V5+,V4+)8O20 · 9H2O | Mon. |
| Corvusite | (Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2O | Mon. 2/m : B2/m |
| Fernandinite | (Ca,K)(V5+,V4+,Fe2+)8O20 · 10H2O | Mon. 2/m : B2/m |
| Straczekite | (Ca,K,Ba)(V5+,V4+)8O20 · 3H2O | Mon. 2/m : B2/m |
Common Associates
Associations Based on Photo Data:
| 8 photos of Bokite associated with Metatyuyamunite | Ca(UO2)2(VO4)2 · 3H2O |
| 5 photos of Bokite associated with Mikehowardite | Fe3+4(V5+O4)4(H2O)2 · H2O |
| 4 photos of Bokite associated with Donowensite | Ca(H2O)3Fe3+2(V2O7)2 |
| 3 photos of Bokite associated with 'Sericite' | KAl2(AlSi3O10)(OH)2 |
| 2 photos of Bokite associated with Corvusite | (Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2O |
| 2 photos of Bokite associated with Baryte | BaSO4 |
| 2 photos of Bokite associated with Roscoelite | KV3+2(AlSi3O10)(OH)2 |
| 1 photo of Bokite associated with Fervanite | Fe3+4V5+4O16 · 5H2O |
| 1 photo of Bokite associated with Steigerite | Al(VO4) · 3H2O |
| 1 photo of Bokite associated with Vashegyite | Al11(PO4)9(OH)6 · 38H2O |
Related Minerals - Strunz-mindat Grouping
| 4.HE.05 | Melanovanadite | Ca(V5+,V4+)4O10 · 5H2O |
| 4.HE.10 | Shcherbinaite | V5+2O5 |
| 4.HE.15 | Hewettite | CaV6O16 · 9H2O |
| 4.HE.15 | Metahewettite | CaV6O16 · 3H2O |
| 4.HE.20 | Bariandite | Al0.6(V5+,V4+)8O20 · 9H2O |
| 4.HE.20 | Corvusite | (Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2O |
| 4.HE.20 | Fernandinite | (Ca,K)(V5+,V4+,Fe2+)8O20 · 10H2O |
| 4.HE.20 | Straczekite | (Ca,K,Ba)(V5+,V4+)8O20 · 3H2O |
| 4.HE.25 | Häggite | V3+V4+O2(OH)3 |
| 4.HE.30 | Doloresite | V4+3O4(OH)4 |
| 4.HE.35 | Duttonite | V4+O(OH)2 |
| 4.HE.40 | Cavoite | CaV4+3O7 |
Other Information
Thermal Behaviour:
Melts at 950 C.
Notes:
Slightly soluble in cold acids with the formation of a pale green solution, dissolves completely in 40% KOH or NaOH. Heated in the closed tube it gives off acid water.
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 Bokite
mindat.org URL:
https://www.mindat.org/min-709.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Bokite
Localities for Bokite
Showing 10 localities.
symbol to view information about a locality.
The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
Kazakhstan | |
| Pekov (1998) |
| Ankinovich (1963) +2 other references |
| Pekov (1998) |
| Ankinovich (1963) +2 other references |
USA | |
| Haynes (1991) +1 other reference |
| Howard +1 other reference |
| Anthony (1997) |
| Walstrom (n.d.) +3 other references |
| Castor et al. (2004) | |
| Anthony (1997) |
Quick NavTopAbout BokiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Balasauskandyk V Deposit, Shieli District, Kyzylorda Region, Kazakhstan