Mineralogy Database

Jedwabite Mineral Data

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General Jedwabite Information

Help on Chemical  Formula: Chemical Formula: Fe7(Ta,Nb)3
Help on Composition: Composition: Molecular Weight = 708.80 gm
   Tantalum  38.29 %  Ta
   Niobium    6.55 %  Nb
   Iron      55.15 %  Fe
            100.00 % 
Help on Empirical Formula: Empirical Formula: Fe0+7Ta1.5Nb0.5
Help on Environment: Environment: Discovered in platiniferous placers in the Nizhnetagilsky District in the Middle Urals, in a collection made by P. Walther at the beginning of the 20th century, in association with niobocarbide and a tantalum carbide.
Help on IMA Status: IMA Status: Approved IMA 1995 (Dana # Added)
Help on Locality: Locality: Nijniy-Tagil, near Solovjeva mountains (formerly Aurorinsky mine) and Baranchinsky massif near the Aktai River, Middle Urals, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: For Jacques Jedwab, Universite Libre de Bruxelles, Belgique, in recognition of his meticulous investigations of the mineralogy of placers and of carbides in natural environments.
Help on Name Pronunciation: Name Pronunciation: Jedwabite + Pronunciation Say JEDWABITE
Help on Synonym: Synonym: IMA1995-043

Jedwabite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:1.63617
Help on Cell Dimensions: Cell Dimensions: a = 4.81, c = 7.87, Z = 1; V = 157.69 Den(Calc)= 7.46
Help on Crystal System: Crystal System: Hexagonal - Dihexagonal Pyramidal H-M Symbol (6mm) Space Group: P 63mmc, P 63mc
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.05(1), 1.347(0.8), 2.19(0.7),

Physical Properties of Jedwabite

Help on Cleavage: Cleavage: None
Help on Color: Color: Grayish yellow.
Help on Density: Density: 8.6
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 7 - Quartz
Help on Luster: Luster: Metallic

Optical Properties of Jedwabite

Help on RL Anisotrophism: RL Anisotrophism: Negligible.
Help on RL Bireflectance: RL Bireflectance: Negligible.
Help on RL Color: RL Color: Grayish white.
Help on RL Pleochroism: RL Pleochroism: None.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Jedwabite in Air
λ R  ∑ R(λ) 
 420 nm   50.00   
 440 nm   52.60 
 460 nm   55.40 
 480 nm   55.30 
 500 nm   57.30 
 520 nm   59.00 
 540 nm   60.80 
 560 nm   60.80 
 580 nm   62.40 
 600 nm   60.40 
 640 nm   62.40 
 650 nm   62.40 
 680 nm   62.20 
 700 nm   63.30 
Calculated Relative Intensity Colors of Jedwabite in Air
   0%   20%   40%   60%   80% 100% 120% 140% 160% 170%

Calculated Properties of Jedwabite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=6.57 gm/cc
note: Specific Gravity of Jedwabite =7.46 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEJedwabite = 476.49 barns/electron
U=PEJedwabite x rElectron Density=3,129.34 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Jedwabite is Not Radioactive

Jedwabite Classification

Help on  Dana Class: Dana Class: (01)Native Elements
  (01.01)with metallic elements other than the platinum group
  (01.01.24)Dana Group Jedwabite! Fe7(Ta,Nb)3 P 63mmc, P 63mc 6mm
Help on  Strunz Class: Strunz Class: 01.AE.25 01 - ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
  01.A - Metals and Intermetallic Alloys
  01.AE -Iron-chromium family
01.AE.25 Jedwabite! Fe7(Ta,Nb)3 P 63mmc, P 63mc 6mm

Other Jedwabite Information

Help on References: References: NAME( MinRec) PHYS. PROP.(Am.Min.,Vol.83,p654,1998) OPTIC PROP.(AmMin, v 83, p 654)
Help on See Also: See Also: Links to other databases for Jedwabite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

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Dana No: Strunz No: 01.AE.25





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