Bismutotantalite Mineral Data

General Bismutotantalite Information

Chemical Formula:

Bi(Ta,Nb)O4

Composition:

Molecular Weight = 436.32 gm

Tantalum 33.18 % Ta 40.51 % Ta₂O₅

Niobium 4.26 % Nb 6.09 % Nb₂O₅

Bismuth 47.90 % Bi 53.40 % Bi₂O₃

Oxygen 14.67 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

BiTa_0.8Nb_0.2O₄

Environment:

In a pegmatite.

IMA Status:

Valid Species (Pre-IMA) 1929

Locality:

Gamba Hill, Busiro Co., Uganda. Link to MinDat.org Location Data.

Name Origin:

Named for its composition (Bi, Ta).

Name Pronunciation:

Bismutotantalite + Pronunciation

Bismutotantalite Image

Images:

Bismutotantalite

Comments: Tan coatings of bismutotantalite on white feldspar with pink lepidolite.
Location: Harding Mine, Taos County, New Mexico, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bismutotantalite Crystallography

Axial Ratios:

a:b:c =0.4788:1:0.4214

Cell Dimensions:

a = 5.633, b = 11.763, c = 4.957, Z = 4; V = 328.46 Den(Calc)= 8.82

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcmn

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

By Intensity(I/I_o): 3.148(1), 2.945(0.6), 3.555(0.3),

Forms:

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Forms: ( 1 3 0) ( 0 1 0) ( 1 1 1) ( 1 0 1) ( 1 1 0)

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Physical Properties of Bismutotantalite

Cleavage:

{010} Perfect, {101} Distinct

Color:

Light brown, Black.

Density:

8.51 - 8.84, Average = 8.67

Diaphaneity:

Subtranslucent to Opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5 - Apatite

Luster:

Adamantine - Metallic

Streak:

yellowish brown

Optical Properties of Bismutotantalite

Gladstone-Dale:

CI meas= -0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.002 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1594,KPDmeas= 0.1621,KC= 0.1592
Ncalc = 2.35 - 2.41

Optical Data:

Biaxial (+), a=2.388, b=2.403, g=2.428, bire=0.0400, 2V(Calc)=78, 2V(Meas)=80. Dispersion r < v.

Calculated Properties of Bismutotantalite

Electron Density:

Bulk Density (Electron Density)=7.34 gm/cc
note: Specific Gravity of Bismutotantalite =8.82 gm/cc.

Fermion Index:

Fermion Index = 0.0001106965
Boson Index = 0.9998893035

Photoelectric:

PE_{Bismutotantalite}=1,343.63 barns/electron
U=PE_{Bismutotantalite} x rElectron Density=9,864.90 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Bismutotantalite is Not Radioactive

Bismutotantalite Classification

Dana Class:

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

(08.01)where A BO4

(08.01.06)Stibiocolumbite Group

08.01.06.01 Stibiocolumbite SbNbO4 Pc21n mm2

08.01.06.02 Stibiotantalite SbTaO4 Pc21n mm2

08.01.06.03 Bismutotantalite Bi(Ta,Nb)O4 Pcmn 2/m 2/m 2/m

08.01.06.04 Bismutocolumbite Bi(Nb,Ta)O4 Pcnn 2/m 2/m 2/m

Strunz Class:

04.DE.30 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

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

04.DE -With medium-sized cations; with various polyhedra

04.DE.30 Cervantite SbSbO4 Pbn21 mm2

04.DE.30 Bismutotantalite Bi(Ta,Nb)O4 Pcmn 2/m 2/m 2/m

04.DE.30 Bismutocolumbite Bi(Nb,Ta)O4 Pcnn 2/m 2/m 2/m

04.DE.30 Clinocervantite! SbSbO4 C 2/c 2/m

04.DE.30 Stibiocolumbite SbNbO4 Pc21n mm2

04.DE.30 Stibiotantalite SbTaO4 Pc21n mm2

Other Bismutotantalite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Bismutotantalite :
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

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Bismutotantalite

Bi(Ta,Nb)O4
Dana No: 08.01.06.03 Strunz No: 04.DE.30
Locality:

Notes:

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