Columbite-(Fe) Mineral Data

General Columbite-(Fe) Information

Chemical Formula:

Fe++Nb2O6

Composition:

Molecular Weight = 337.66 gm

Niobium 55.03 % Nb 78.72 % Nb₂O₅

Iron 16.54 % Fe 21.28 % FeO

Oxygen 28.43 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Nb₂O₆

Environment:

Pegmatites, and alluvial deposits.

IMA Status:

Valid Species (Pre-IMA) 1802

Locality:

M'buye Mine, Rwanda. Link to MinDat.org Location Data.

Name Origin:

Named after its content of the element niobium, formerly called columbium and the Latin ferrium - "iron."

Name Pronunciation:

Columbite-(Fe) + Pronunciation

Synonym:

Coltan

Columbite-Tantalite

Ferrocolumbite - Renamed to Columbite-(Fe) by Mineralogical Record, v39 (2008), p 131

Niobite

Columbite-(Fe) Image

Images:

Click Here for Larger Columbite-(Fe) Image

Columbite-(Fe) Microcline

Comments: Blocky, dark brown ferrocolumbite on pale greenish blue amazonite (microcline).
Location: Crystal Park, El Paso Co., Colorado, USA. Scale: 2.5 x 1.5 cm.
© Fabre Minerals

Images:

Columbite-(Fe) Baotite

Comments: Minute brown crystalline grains of baotite in dark ferrocolumbite (columbite-(Fe)).
Location: Sheep Creek, Ravalli County, Montana. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Columbite-(Fe) Plumbopyrochlore

Comments: Brown plumbopyrochlore crystal with dark brown ferrocolumbite (columbite-(Fe)).
Location: Holdazan, Buregteg, Mongolia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Columbite-(Fe)

Comments: Dark, coaly black, weathered granular ferrocolumbite. This specimen was originally identified as samarskite-(Y) and corrected by Fred Davis who studied the locality.
Location: Spinelli Samarskite Prospect, Glastonbury, Hartford Co., Connecticut, USA. Scale: Picture size 4 mm.
© Paul M. Schumacher

Images:

Columbite-(Fe)

Comments: Dark grains of columbite-(Fe) wtth small brown grains of fluorcarbonates of LREE. Corrected identificaton by Pavel M. Kartashov who analyzed this occurrence of 'chagbaiite'.
Location: Round Top Rhyolite, Hudspeth County, Texas, USA. Scale: Picture Size 1 mm.
© Thomas Witzke

Images:

Columbite-(Fe) Upalite

Comments: Thin translucent yellowish upalite crusts on a prismatic, black columbite crystal.
Location: Thin translucent yellowish crusts on undifferntiated columbite crystal. Scale: Picture Size 2 mm.
© Jeff Weissman / Photographic Guide to Mineral Species

Columbite-(Fe) Crystallography

Axial Ratios:

a:b:c =0.4015:1:0.3546

Cell Dimensions:

a = 5.746, b = 14.308, c = 5.075, Z = 4; V = 417.23 Den(Calc)= 5.38

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pcan

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

By Intensity(I/I_o): 2.977(1), 3.675(0.4), 1.726(0.16),

Crystal Structure:

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drag2 - RMB Resize/Rotate
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Tarantino S C , Zema M , Pistorino M , Domeneghetti M C , Physics and Chemistry of Minerals , 30 (2003) p.590-598, High-temperature X-ray investigation of natural columbites, Note: sample BRA3 at T = 600 C, Locality: San Jose de Safira, Minas Gerais, Brazil

Physical Properties of Columbite-(Fe)

Cleavage:

{010} Distinct

Color:

Black, Brownish black.

Density:

5.3 - 7.3, Average = 6.3

Diaphaneity:

Translucent to opaque

Fracture:

Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

6 - Orthoclase

Luminescence:

Non-fluorescent.

Luster:

Sub Metallic

Streak:

blackish brown

Optical Properties of Columbite-(Fe)

Gladstone-Dale:

CI meas= 0.149 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.25,KPDmeas= 0.2135,KC= 0.251
Ncalc = 2.33 - 2.83

Optical Data:

Biaxial (+), b=2.29-2.4

RL Color:

Grayish white with a brownish tint and reddish internal reflections.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Columbite-(Fe) in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	18.40	19.10
420 nm	17.70	18.60
440 nm	17.30	18.20
460 nm	17.10	17.90
480 nm	16.90	17.70
500 nm	16.90	17.60
520 nm	16.80	17.50
540 nm	16.80	17.40
560 nm	16.70	17.30
580 nm	16.70	17.20
600 nm	16.70	17.20
620 nm	16.60	17.10
640 nm	16.50	17.10
660 nm	16.40	16.90
680 nm	16.30	16.80
700 nm	16.10	16.80

**Calculated Relative Intensity Colors of Columbite-(Fe) in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	530%
R₁
R₂

Calculated Properties of Columbite-(Fe)

Electron Density:

Bulk Density (Electron Density)=4.97 gm/cc
note: Specific Gravity of Columbite-(Fe) =5.38 gm/cc.

Fermion Index:

Fermion Index = 0.0036428616
Boson Index = 0.9963571384

Photoelectric:

PE_{Columbite-(Fe)}= 89.38 barns/electron
U=PE_{Columbite-(Fe)} x rElectron Density= 444.33 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Columbite-(Fe) is Not Radioactive

Columbite-(Fe) Classification

Dana Class:

08.03.02.02 (08)Multiple Oxides with Nb, Ta, and Ti

(08.03)where A (B2O6)

(08.03.02)Tantalite - Columbite Series

08.03.02.01 Tantalite-(Fe) FeTa2O6 Pcan 2/m 2/m 2/m

08.03.02.02 Columbite-(Fe) FeNb2O6 Pcan 2/m 2/m 2/m

08.03.02.03 Tantalite-(Mn) MnTa2O6 Pcan 2/m 2/m 2/m

08.03.02.04 Columbite-(Mn) (Mn,Fe)(Nb,Ta)2O6 Pcan 2/m 2/m 2/m

08.03.02.05 Columbite-(Mg) (Mg,Fe,Mn)(Nb,Ta)2O6 Pcan 2/m 2/m 2/m

08.03.02.06 Tantalite-(Mg)! (Mg,Fe)(Ta,Nb)2O6 P bcn 2/m 2/m 2/m

Strunz Class:

04.DB.35 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DB -With medium-sized cations; chains of edge-sharing octahedra

04.DB.35 Columbite-(Mg) (Mg,Fe,Mn)(Nb,Ta)2O6 Pcan 2/m 2/m 2/m

04.DB.35 Tantalite-(Fe) FeTa2O6 Pcan 2/m 2/m 2/m

04.DB.35 Columbite-(Fe) FeNb2O6 Pcan 2/m 2/m 2/m

04.DB.35 Columbite-(Mn) (Mn,Fe)(Nb,Ta)2O6 Pcan 2/m 2/m 2/m

04.DB.35 Qitianlingite Fe2Nb2WO10 P bcn 2/m 2/m 2/m

04.DB.35 Tantalite-(Mn) MnTa2O6 Pcan 2/m 2/m 2/m

04.DB.35 Tantalite-(Mg)! (Mg,Fe)(Ta,Nb)2O6 P bcn 2/m 2/m 2/m

Other Columbite-(Fe) Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

See Also:

Links to other databases for Columbite-(Fe) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Print or Cut-and-Paste your Columbite-(Fe) Specimen Label here :

Columbite-(Fe)

Fe++Nb2O6
Dana No: 08.03.02.02 Strunz No: 04.DB.35
Locality:

Notes: