Straczekite
A valid IMA mineral species
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About Straczekite
Formula:
(Ca,K,Ba)(V5+,V4+)8O20 · 3H2O
Colour:
Green-black
Lustre:
Greasy
Hardness:
1 - 2
Specific Gravity:
3.09 - 3.29
Crystal System:
Monoclinic
Member of:
Name:
Named in honor of John A. Straczek (13 September 1914, Washington, USA - 2 November 2003, Connecticut, USA), chief geologist, Union Carbide Corporation, who made possible the study of the mineral. Pronounced strā'chek-ite. *Birth/death details, other than birth year, unverified.
This page provides mineralogical data about Straczekite.
Unique Identifiers
Mindat ID:
3796
Long-form identifier:
mindat:1:1:3796:5
GUID
(UUID V4):
(UUID V4):
e7bb4912-dca4-4a70-b699-979a64cf6905
IMA Classification of Straczekite
Approved
Approval year:
1983
First published:
1984
Classification of Straczekite
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
47.3.2.1
47 : VANADIUM OXYSALTS
3 : Hydrated Normal Vanadium Oxysalts
47 : VANADIUM OXYSALTS
3 : Hydrated Normal Vanadium Oxysalts
21.2.15
21 : Vanadates (and vanadates with arsenate or phosphate)
2 : Vanadates of Mg, Ca, Sr or Ba
21 : Vanadates (and vanadates with arsenate or phosphate)
2 : Vanadates of Mg, Ca, Sr or Ba
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 |
---|---|---|
Szk | 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 Straczekite
Greasy
Transparency:
Opaque
Colour:
Green-black
Streak:
Greenish black
Hardness:
1 - 2 on Mohs scale
Cleavage:
Perfect
{100}
{100}
Density:
3.09 - 3.29 g/cm3 (Measured) 3.21 g/cm3 (Calculated)
Optical Data of Straczekite
Type:
Biaxial (-)
RI values:
nα = 2.000
Max Birefringence:
δ = 2.000
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
relatively weak
Pleochroism:
Weak
Comments:
apple-green to olive-green
Chemistry of Straczekite
Mindat Formula:
(Ca,K,Ba)(V5+,V4+)8O20 · 3H2O
Crystallography of Straczekite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 11.679(3) Å, b = 3.6608(4) Å, c = 10.636(2) Å
β = 100.53(4)°
β = 100.53(4)°
Ratio:
a:b:c = 3.19 : 1 : 2.905
Unit Cell V:
447.08 ų (Calculated from Unit Cell)
Z:
1
Twinning:
On {001}, possible, observed by X-ray diffraction.
Crystal Structure
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2x2x2 | 3x3x3 | 4x4x4
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
---|---|---|---|---|---|---|---|
0010852 | Straczekite | Kutoglu A (1983) Kristallstruktur der calcium-vanadium-bronze CaxV4+2xV5+(2-2x)O5 Zeitschrift fur Kristallographie 162 263-272 | 1983 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
10.449 Å | (50) |
3.486 Å | (100) |
3.255 Å | (10) |
2.492 Å | (10) |
1.9437 Å | (15) |
1.8306 Å | (50) |
1.8030 Å | (10) |
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] |
Type Occurrence of Straczekite
General Appearance of Type Material:
Dark greenish-black crystals as thin laths up to 0.5 mm in length, forming thick masses.
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
A rare secondary mineral in fibrous seams in gangue.
Associated Minerals at Type Locality:
Reference:
Evans, Jr., H.T., Nord, G., Marinenko, J. and Milton, C. (1984) Straczekite, a new calcium barium potassium vanadate mineral from Wilson Springs, Arkansas. Mineralogical Magazine: 48: 289-293.
Synonyms of Straczekite
Other Language Names for Straczekite
German:Straczekit
Spanish:Straczekita
Relationship of Straczekite to other Species
Member of:
Other Members of this group:
Bariandite | Al0.6(V5+,V4+)8O20 · 9H2O | Mon. |
Bokite | (Al,Fe)1.3(V5+,V4+,Fe3+)8O20 · 7.5H2O | 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 |
Common Associates
Associated Minerals Based on Photo Data:
11 photos of Straczekite associated with Miserite | K1.5-x(Ca,Y,REE)5(Si6O15)(Si2O7)(OH,F)2 · yH2O |
11 photos of Straczekite associated with Wollastonite | Ca3(Si3O9) |
1 photo of Straczekite associated with Calcite | CaCO3 |
1 photo of Straczekite associated with Francevillite | Ba(UO2)2(VO4)2 · 5H2O |
1 photo of Straczekite associated with Quartz | SiO2 |
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 | Bokite | (Al,Fe)1.3(V5+,V4+,Fe3+)8O20 · 7.5H2O |
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.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
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 Straczekite
mindat.org URL:
https://www.mindat.org/min-3796.html
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References for Straczekite
Reference List:
Localities for Straczekite
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).
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.
All localities listed without proper references should be considered as questionable.
Germany | |
| Witzke et al. (2001) |
USA | |
| Evans et al. (1990) +1 other reference |
| Howard +2 other references |
|
Quick NavTopAbout StraczekiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
North Wilson pit, Union Carbide Mine, Wilson Springs, Garland County, Arkansas, USA