Mineralogy Database

Straczekite Mineral Data

Search Webmineral :

General Straczekite Information

Help on Chemical  Formula: Chemical Formula: (Ca,K,Ba)(V5+,V4+)8O20•3H2O
Help on Composition: Composition: Molecular Weight = 831.07 gm
   Potassium   1.41 %  K     1.70 % K2O
   Barium      1.65 %  Ba    1.84 % BaO
   Calcium     2.89 %  Ca    4.05 % CaO
   Vanadium   49.04 %  V    19.96 % VO2 / 65.65 % V2O5
   Hydrogen    0.73 %  H     6.50 % H2O
   Oxygen     44.28 %  O
             ______        ______ 
             100.00 %       99.71 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca0.6K0.3Ba0.1V5+6V4+2O20•3(H2O)
Help on IMA Status: IMA Status: Approved IMA 1983
Help on Locality: Locality: Union Carbide mine, Wilson Springs, Arkansas, USA Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for John A. Straczed (1914-), U. S. Geologist.
Help on Name Pronunciation: Name Pronunciation: Straczekite + Pronunciation Say STRACZEKITE

Straczekite Image

Click Here for Larger   Image in a New Browser Window Images:
Click Here for Larger   Image


Comments: Greenish-black, prismatic-acicular crystals of straczekite.
Location: Union Carbide Mine, Wilson Springs (Potash Sulfur Springs), Garland Co., Arkansas, USA. Scale: Picture size 1.5 mm.
© Thomas Witzke / Abraxas-Verlag

Straczekite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =3.1902:1:2.9053
Help on Cell Dimensions: Cell Dimensions: a = 11.679, b = 3.6608, c = 10.636, Z = 1; beta = 100.53° V = 447.08 Den(Calc)= 3.09
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.486(1), 1.8306(0.5), 10.449(0.5),

Physical Properties of Straczekite

Help on Cleavage: Cleavage: {100} Perfect
Help on Color: Color: Greenish black.
Help on Density: Density: 3.19 - 3.21, Average = 3.2
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Hardness: Hardness: 1-2 - Between Talc and Gypsum
Help on Luster: Luster: Greasy (Oily)
Help on Streak: Streak: greenish black

Optical Properties of Straczekite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.075 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.3236,KPDmeas= 0.3125,KC= 0.338
Ncalc = 2.04 - 2.08
Help on Optical Data: Optical Data: Biaxial (-), a=2, 2V(Meas)=large.
Help on Pleochroism (x): Pleochroism (x): green.
Help on Pleochroism (y): Pleochroism (y): green.
Help on Pleochroism (z): Pleochroism (z): green.

Calculated Properties of Straczekite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.95 gm/cc
note: Specific Gravity of Straczekite =3.09 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0044252129
Boson Index = 0.9955747871
Help on Photoelectric: Photoelectric: PEStraczekite = 16.88 barns/electron
U=PEStraczekite x relectron= 49.88 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 19.49 (Gamma Ray American Petroleum Institute Units)
Concentration of Straczekite per GRapi unit = 5.13 (%)

Estimated Radioactivity from Straczekite - barely detectable


Straczekite Classification

Help on  Dana Class: Dana Class: (47)Vanadium Oxysalts
  (47.03.02)Straczekite Group Straczekite (Ca,K,Ba)(V5,V4)8O20•3H2O C 2/m 2/m Corvusite (Na,Ca,K)V8O20•4(H2O) C 2/m 2/m Fernandinite CaV8O20•4(H2O) C 2/m 2/m Bariandite Al0.6V8O20•9(H2O) C 2/c 2/m Bokite (Al,Fe)1.3(V,Fe)8O20•4.7(H2O) C 2/m 2/m Kazakhstanite Fe5V3V12O39(OH)9•9(H2O) C 2/m 2/m
Help on  Strunz Class: Strunz Class: 04.HE.20 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.H - V[5,6] Vanadates
  04.HE -Phyllovanadates
04.HE.20 Bokite (Al,Fe)1.3(V,Fe)8O20•4.7(H2O) C 2/m 2/m
04.HE.20 Bariandite Al0.6V8O20•9(H2O) C 2/c 2/m
04.HE.20 Corvusite (Na,Ca,K)V8O20•4(H2O) C 2/m 2/m
04.HE.20 Fernandinite CaV8O20•4(H2O) C 2/m 2/m
04.HE.20 Straczekite (Ca,K,Ba)(V5,V4)8O20•3H2O C 2/m 2/m

Other Straczekite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Straczekite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

Search for Straczekite using:

Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Straczekite :

Ask about Straczekite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Espaņol

Print or Cut-and-Paste your Straczekite Specimen Label here :


Dana No: Strunz No: 04.HE.20





Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.