Jedwabite Mineral Data

Jedwabite Mineral Data +

General Jedwabite Information

Chemical Formula:

Fe7(Ta,Nb)3

Composition:

Molecular Weight = 708.80 gm

Tantalum 38.29 % Ta

Niobium 6.55 % Nb

Iron 55.15 % Fe

______

100.00 %

Empirical Formula:

Fe⁰⁺₇Ta_1.5Nb_0.5

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.

IMA Status:

Approved IMA 1995 (Dana # Added)

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.

Name Origin:

For Jacques Jedwab, Université Libre de Bruxelles, Belgique, in recognition of his meticulous investigations of the mineralogy of placers and of carbides in natural environments.

Synonym:

IMA1995-043

Jedvabite

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Jedwabite Crystallography

Axial Ratios:

a:c = 1:1.63617

Cell Dimensions:

a = 4.81, c = 7.87, Z = 1; V = 157.69 Den(Calc)= 7.46

Crystal System:

Hexagonal - Dihexagonal PyramidalH-M Symbol (6mm) Space Group: P 6₃mmc, P 6₃mc

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.05(1), 1.347(0.8), 2.19(0.7),

Physical Properties of Jedwabite

Cleavage:

None

Color:

Grayish yellow.

Density:

8.6

Diaphaniety:

Opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Hardness:

7 - Quartz

Luster:

Metallic

Optical Properties of Jedwabite

RL Anisotrophism:

Negligible.

RL Bireflectance:

Negligible.

RL Color:

Grayish white.

RL Pleochroism:

None.

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**
Relative Intensity	0%	20%	40%	60%	80%	100%	120%	140%	160%	170%
R

Calculated Properties of Jedwabite

Electron Density:

r_electron=6.57 gm/cc
note: r_Jedwabite=7.46 gm/cc.

Fermion Index

Fermion Index = 0.01173
Boson Index = 0.98827

Photoelectric:

PE_Jedwabite= 476.49 barns/electron
U=PE_Jedwabite x r_electron=3,129.34 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Jedwabite is Not Radioactive

Jedwabite Classification

Dana Class:

1.1.24.1 (1)Native Elements

(1.1)with metallic elements other than the platinum group

(1.1.24)Dana Group

1.1.24.1 Jedwabite ! Fe7(Ta,Nb)3 P 6₃mmc, P 6₃mc 6mm

Strunz Class:

I/A.08-50 I - Elements

I/A - Metallic and intermetallic compounds, Carbides, Nitrides, Phosphides and Silicides

I/A.08 - Nickel series

I/A.08-10 Nickel Ni F m3m 4/m 3 2/m

I/A.08-20 Taenite gamma-(Fe,Ni) F m3m 4/m 3 2/m

I/A.08-30 Tetrataenite FeNi P 4/mmm 4/m 2/m 2/m

I/A.08-40 Awaruite Ni2FetoNi3Fe P m3m 4/m 3 2/m

I/A.08-50 Jedwabite Fe7(Ta,Nb)3 P 6₃mmc, P 6₃mc 6mm

Other Jedwabite Information

References:

NAME( MinRec) PHYS. PROP.(Am.Min.,Vol.83,p654,1998) OPTIC PROP.(AmMin, v 83, p 654)

See Also:

Links to other databases for Jedwabite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -Handbook of Mineralogy (UofA) 6 -MinDAT 7 -MinMax(Deutsch) 8 -MinMax(English) 9 -Mineralienatlas (Deutsch) 10 -QUT Mineral Atlas

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

Jedwabite

Fe7(Ta,Nb)3
Dana No: 1.1.24.1 Strunz No: I/A.08-50
Locality:

Notes: