Tantalite-(Fe) Mineral Data
General Tantalite-(Fe) Information
Chemical Formula:
Fe++Ta2O6
Composition:
Molecular Weight = 513.74 gm
Tantalum 70.44 % Ta 86.02 % Ta2 O5
Iron 10.87 % Fe 13.98 % FeO
Oxygen 18.69 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Fe2+ Ta2 O6
Environment:
Accessory mineral in granite pegmatites.
IMA Status:
Approved IMA 1989
Locality:
Upper Bear Gulch, Lawrence Co, South Dakota, USA Link to MinDat.org Location Data.
Name Origin:
Named for the FERROus iron and from the Greek, Tantalos = father of Niobe.
Synonym:
Coltan
Columbite-Tantalite
Ferrotantalite - Renamed to Tantalite-(Fe) by Mineralogical Record, v39 (2008), p 131
Tantalite-(Fe) Image
Images:
Images:
Tantalite-(Fe)
Comments: Blocky, crystalline aggregate of ferrotantalite crystals weighing over one kilogram.
Location: Ecuador, Minas Gerais, Brazil.
Scale: 10 x 6 x 5 cm.
© Rob Lavinsky
Tantalite-(Fe) Crystallography
Axial Ratios:
a:b:c =0.4023:1:0.3567
Cell Dimensions:
a = 5.73, b = 14.24, c = 5.08, Z = 4; V = 414.50 Den(Calc)= 8.23
Crystal System:
Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcan
X Ray Diffraction:
By Intensity(I/Io ): 2.96(1), 3.66(0.5), 1.721(0.2),
Physical Properties of Tantalite-(Fe)
Cleavage:
{010} Distinct
Color:
Brownish black, Black.
Density:
8.2
Diaphaneity:
Opaque
Fracture:
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Hardness:
6-6.5 - Orthoclase-Pyrite
Luster:
Sub Metallic
Streak:
black brown
Optical Properties of Tantalite-(Fe)
Gladstone-Dale:
CI meas = -0.052 (Good) - where the CI = (1-KPDmeas /KC ) CI calc = -0.048 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.1636,KPDmeas = 0.1642,KC = 0.1562 Ncalc = 2.28 - 2.29
Optical Data:
Biaxial (+), a=2.26, b=2.3-2.4, g=2.43, bire=0.1700
Calculated Properties of Tantalite-(Fe)
Electron Density:
Bulk Density (Electron Density)=7.05 gm/cc note: Specific Gravity of Tantalite-(Fe) =8.23 gm/cc.
Fermion Index:
Fermion Index = 0.0024788106 Boson Index = 0.9975211894
Photoelectric:
PETantalite-(Fe) = 850.67 barns/electronU=PETantalite-(Fe) x r Electron Density=5,996.10 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Tantalite-(Fe) is Not Radioactive
Tantalite-(Fe) Classification
Dana Class:
08.03.02.01 (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 Tantalite-(Fe) Information
References:
PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Tantalite-(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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Tantalite-(Fe)
Fe++Ta2O6
Dana No: 08.03.02.01 Strunz No: 04.DB.35
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