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Bismutomicrolite

Big Photo

Malkhan pegmatite field (Malchan), Krasny Chikoy, Chitinskaya Oblast', Transbaikalia (Zabaykalye), Eastern-Siberian Region, Russia
© Thomas Witzke

Show Bismutomicrolite Photos (2)
Formula:
(Bi,Ca)(Ta,Nb)
 
2
O
 
6
(OH)
System:IsometricColour:Yellow, pink, brown; ...
Hardness:5
Name:Assigned by the IMA Committee on pyrochlore nomenclature for the predominant bismuth content and relation to microlite in the pyrochlore group.


Pyrochlore Group. Microlite Subgroup. The bismuth analogue of the other members of the Microlite Subgroup.

Classification of Bismutomicrolite

IMA status:Approved
Strunz 8th edition ID:4/C.18-70
Nickel-Strunz 10th (pending) edition ID:4.DH.15

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
H : With large (+- medium-sized) cations; sheets of edge-sharing octahedra
Dana 8th edition ID:8.2.2.5

8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
2 : A2B2O6(O,OH,F)
Hey's CIM Ref.:18.1.35

18 : Niobates and Tantalates
1 : Niobates and tantalates containing neither rare earths nor U
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Type Occurrence of Bismutomicrolite

Type Locality:Wampewo Hill, Busiiro Co. (Bushiro Co.), Wakiso District, Uganda
Year of Discovery:1977
Geological Setting of type material:Late hydrothermal replacement of bismutotantalite in a lithium-bearing pegmatite
Associated Minerals at type locality:
WaylanditeBismutotantalite

Occurrences of Bismutomicrolite

Geological Setting:In pegmatites

Physical Properties of Bismutomicrolite

Lustre:Resinous, Dull
Diaphaneity (Transparency):Translucent
Colour:Yellow, pink, brown; dark grey to black
Hardness (Mohs):5
Tenacity:Brittle
Fracture:Irregular/Uneven
Density (measured):6.5 g/cm3
Density (calculated):6.9 g/cm3

Crystallography of Bismutomicrolite

Crystal System:Isometric
Class (H-M):m3m (4/m 3 2/m) - Hexoctahedral
Space Group:Fd3m (F41/d 3 2/m)
Cell Parameters:a = 10.46Å
Unit Cell Volume:V 1,144.45 ų (Calculated from Unit Cell)
Z:8
Morphology:Rarely octahedral crystals; commonly massive, in veinlets.
X-Ray Powder Diffraction:
d-spacingIntensity
2.997 (vvs)
1.838 (vs)
1.568 (vs)
3.136 (s)
5.94 (ms)
2.595 (ms)
Comments:Recorded on material from the Tromba pegmatite, Brazil

Optical Data of Bismutomicrolite

Type:Isotropic
RI values: n = 2
Maximum Birefringence:δ = 0.000 - Isotropic minerals have no birefringence
Surface Relief:Very High

Chemical Properties of Bismutomicrolite

Formula:
(Bi,Ca)(Ta,Nb)
 
2
O
 
6
(OH)
Essential elements:Bi, H, O, Ta
All elements listed in formula:Bi, Ca, H, Nb, O, Ta
Analyical Data:Analyses of material from the type locality (1), and from the Tromba pegmatite, Brazil (2).
Empirical formula calculated from the values given in column (2), after deduction of Fe2O3.
             (1)       (2)

Nb2O5       (5.65)    (6.65)
Ta2O5      (45.49)   (63.10)
SiO2        (0.36)
Al2O3       (0.80)
Fe2O3                 (0.08)
Bi2O3      (40.40)   (25.09)
FeO + MnO   (0.22)
CaO         (1.46)    (3.35)
SrO         (0.92)
Na2O        (0.08)
K2O         (0.09)
Li2O        (0.25)
H2O+        (4.16)    (1.50)
H2O-        (0.04)

sum         99.92     99.77 wt.-%
Empirical Formula:
(Bi
 
0.64
Ca
 
0.36
)
 
=1.00
(Ta
 
1.69
Nb
 
0.31
)
 
=2.00
O
 
6
(OH)
Common Impurities:Al,Fe,K,Li,Mn,Na,Si,Sr

Relationship of Bismutomicrolite to other Species

Related to:
  • Microlite Subgroup
  • Pyrochlore Group
    • Related Minerals - Nickel-Strunz Grouping):
    4.DH.05Brannerite
    (U
    4+
     
    		,Ca)(Ti,Fe
    3+
     
    		)
     
    2
    		O
     
    6
    4.DH.05Orthobrannerite
    UTi
     
    4
    		O
     
    12
    		(OH)
     
    2
    4.DH.05Thorutite
    (Th,U,Ca)Ti
     
    2
    		(O,OH)
     
    6
    4.DH.10Kassite
    CaTi
     
    2
    		O
     
    4
    		(OH)
     
    2
    4.DH.10Lucasite-(Ce)
    CeTi
     
    2
    		(O,OH)
     
    6
    4.DH.15Alumotungstite
    (W,Al)(O,OH)
     
    3
    4.DH.15Bariomicrolite
    Ba(Ta,Nb)
     
    2
    		(O,OH)
     
    7
    4.DH.15Bariopyrochlore
    (Ba,Sr)
     
    2
    		(Nb,Ti)
     
    2
    		(O,OH)
     
    7
    4.DH.15Betafite
    (Ca,U)
     
    2
    		(Ti,Nb)
     
    2
    		O
     
    6
    		(OH)
    4.DH.15Calciobetafite
    (Ca,RE,Th,U)
     
    2
    		(Nb,Ta,Ti)
     
    2
    		O
     
    7
    4.DH.15Ceriopyrochlore-(Ce)
    (Ce,Ca,Y)
     
    2
    		(Nb,Ta)
     
    2
    		O
     
    6
    		(OH,F)
    4.DH.15Cesstibtantite
    (Cs,Na)SbTa
     
    4
    		O
     
    12
    4.DH.15Ferritungstite
    (W,Fe
    3+
     
    		)(O,OH)
     
    3
    4.DH.15Jixianite
    Pb(W,Fe
    3+
     
    		)
     
    2
    		(O,OH)
     
    7
    4.DH.15Kalipyrochlore
    (K,Sr)
     
    2-x
    		Nb
     
    2
    		O
     
    6
    		(O,OH)·nH
     
    2
    		O
    4.DH.15Microlite
    (Ca,Na)
     
    2
    		Ta
     
    2
    		O
     
    6
    		(O,OH,F)
    4.DH.15Natrobistantite
    (Na,Cs)Bi(Ta,Nb,Sb)
     
    4
    		O
     
    12
    4.DH.15Plumbopyrochlore
    (Pb,Y,U,Ca)
     
    2-x
    		Nb
     
    2
    		O
     
    6
    		(OH)
    4.DH.15Plumbomicrolite
    (Pb,Ca,U)
     
    2
    		Ta
     
    2
    		O
     
    6
    		(OH)
    4.DH.15Plumbobetafite
    (Pb,U,Ca)(Ti,Nb)
     
    2
    		O
     
    6
    		(OH,F)
    4.DH.15Pyrochlore
    (Ca,Na)
     
    2
    		Nb
     
    2
    		O
     
    6
    		(OH,F)
    4.DH.15Stibiomicrolite
    (Sb,Ca,Na)
     
    2
    		(Ta,Nb)
     
    2
    		O
     
    7
    4.DH.15Strontiopyrochlore
    (Sr,Ce,Ca)
     
    0.66
    		(Nb,Fe)
     
    2
    		(O,OH)
     
    7
    4.DH.15Stannomicrolite
    (Sn,Fe,Mn)
     
    2
    		(Ta,Nb,Sn)
     
    2
    		(O,OH)
     
    7
    4.DH.15Stibiobetafite
    (Sb,Ca)
     
    2
    		(Ti,Nb,Ta)
     
    2
    		(O,OH)
     
    7
    4.DH.15Uranmicrolite
    (U,Ca,Ce)
     
    2
    		(Ta,Nb)
     
    2
    		O
     
    6
    		(OH,F)
    4.DH.15Uranpyrochlore
    (U,Ca,Ce)
     
    2
    		(Nb,Ta)
     
    2
    		O
     
    6
    		(OH,F)
    4.DH.15Yttrobetafite-(Y)
    (Y,U,Ce)
     
    2
    		(Ti,Nb,Ta)
     
    2
    		O
     
    6
    		OH
    4.DH.15Yttropyrochlore-(Y)
    (Y,Na,Ca,U)
     
    1-2
    		(Nb,Ta,Ti)
     
    2
    		(O,OH)
     
    7
    4.DH.15Fluornatromicrolite
    (Na,Ca,Bi)
     
    2
    		Ta
     
    2
    		O
     
    6
    		F
    4.DH.15Bismutopyrochlore
    (Bi,U,Ca,Pb)
     
    1+x
    		(Nb,Ta)
     
    2
    		O
     
    6
    		(OH)·nH
     
    2
    		O
    4.DH.15Thorian Pyrochlore
    4.DH.15Elsmoreite
    WO
     
    3
    		·0.5H
     
    2
    		O
    4.DH.20Bismutostibiconite
    Bi(Sb
    5+
     
    		,Fe
    3+
     
    		)
     
    2
    		O
     
    7
    4.DH.20Bindheimite
    Pb
     
    2
    		Sb
     
    2
    		O
     
    6
    		(O,OH)
    4.DH.20Monimolite
    (Pb,Ca,Fe)
     
    3
    		Sb
     
    2
    		O
     
    7
    4.DH.20Partzite
    Cu
     
    2
    		Sb
     
    2
    		(O,OH)
     
    7
    4.DH.20Roméite
    (Ca,Fe,Mn,Na)
     
    2
    		(Sb,Ti)
     
    2
    		O
     
    6
    		(O,OH,F)
    4.DH.20Stetefeldtite
    Ag
     
    2
    		Sb
     
    2
    		(O,OH)
     
    7
    4.DH.20Stibiconite
    SbSb
     
    2
    		O
     
    6
    		(OH)
    4.DH.25Rosiaite
    PbSb
    5+
    2
    		O
     
    6
    4.DH.30Zirconolite
    CaZrTi
     
    2
    		O
     
    7
    4.DH.35Liandratite
    U(Nb,Ta)
     
    2
    		O
     
    8
    4.DH.35Petscheckite
    UFe(Nb,Ta)
     
    2
    		O
     
    8
    4.DH.40Ingersonite
    Ca
     
    3
    		MnSb
     
    4
    		O
     
    14
    4.DH.45Pittongite
    Na
     
    0.22
    		(W,Fe
    3+
     
    		)(O,OH)
     
    3
    		 · 0.44H
     
    2
    		O
    Related Minerals - Hey's Index Grouping:
    18.1.1Lithiotantite
    Li(Ta,Nb)
     
    3
    		O
     
    8
    18.1.2Lueshite
    NaNbO
     
    3
    18.1.3Natroniobite
    NaNbO
     
    3
    18.1.4Franconite
    Na
     
    2
    		Nb
     
    4
    		O
     
    11
    		·9H
     
    2
    		O
    18.1.5Natrotantite
    Na
     
    2
    		Ta
     
    4
    		O
     
    11
    18.1.6Irtyshite
    Na
     
    2
    		(Ta,Nb)
     
    4
    		O
     
    11
    18.1.7Rankamaite
    (Na,K,Pb,Li)
     
    3
    		(Ta,Nb,Al)
     
    11
    		(O,OH)
     
    30
    18.1.8Kalipyrochlore
    (K,Sr)
     
    2-x
    		Nb
     
    2
    		O
     
    6
    		(O,OH)·nH
     
    2
    		O
    18.1.9Calciotantite
    CaTa
     
    4
    		O
     
    11
    18.1.10Rynersonite
    Ca(Ta,Nb)
     
    2
    		O
     
    6
    18.1.11Microlite
    (Ca,Na)
     
    2
    		Ta
     
    2
    		O
     
    6
    		(O,OH,F)
    18.1.12Belyankinite
    Ca
     
    1-2
    		(Ti,Zr,Nb)
     
    5
    		O
     
    12
    		 · 9H
     
    2
    		O (?)
    18.1.13Latrappite
    (Ca,Na)(Nb,Ti,Fe)O
     
    3
    18.1.14Hochelagaite
    (Ca,Na,Sr)(Nb,Ti,Si,Al)
     
    4
    		O
     
    11
    		·8H
     
    2
    		O
    18.1.15Bariomicrolite
    Ba(Ta,Nb)
     
    2
    		(O,OH)
     
    7
    18.1.16Parabariomicrolite
    BaTa
     
    4
    		O
     
    10
    		(OH)
     
    2
    		·2H
     
    2
    		O
    18.1.17Bariopyrochlore
    (Ba,Sr)
     
    2
    		(Nb,Ti)
     
    2
    		(O,OH)
     
    7
    18.1.18Alumotantite
    AlTaO
     
    4
    18.1.19Simpsonite
    Al
     
    4
    		(Ta,Nb)
     
    3
    		O
     
    13
    		(OH,F)
    18.1.20Sosedkoite
    (K,Na)
     
    5
    		Al
     
    2
    		(Ta,Nb)
     
    22
    		O
     
    60
    18.1.21Thoreaulite
    SnTa
     
    2
    		O
     
    6
    18.1.22Stannomicrolite
    (Sn,Fe,Mn)
     
    2
    		(Ta,Nb,Sn)
     
    2
    		(O,OH)
     
    7
    18.1.23Foordite
    (Sn,Pb)(Nb,Ta)
     
    2
    		O
     
    6
    18.1.24Changbaiite
    PbNb
     
    2
    		O
     
    6
    18.1.25Plumbopyrochlore
    (Pb,Y,U,Ca)
     
    2-x
    		Nb
     
    2
    		O
     
    6
    		(OH)
    18.1.26Plumbomicrolite
    (Pb,Ca,U)
     
    2
    		Ta
     
    2
    		O
     
    6
    		(OH)
    18.1.27Stibiocolumbite
    Sb(Nb,Ta)O
     
    4
    18.1.28Stibiotantalite
    Sb(Ta,Nb)O
     
    4
    18.1.29Natrobistantite
    (Na,Cs)Bi(Ta,Nb,Sb)
     
    4
    		O
     
    12
    18.1.30Cesplumtantite
    (Cs,Na)
     
    2
    		(Pb,Sb
    3+
     
    		)
     
    3
    		Ta
     
    8
    		O
     
    24
    18.1.31Stibiomicrolite
    (Sb,Ca,Na)
     
    2
    		(Ta,Nb)
     
    2
    		O
     
    7
    18.1.32Cesstibtantite
    (Cs,Na)SbTa
     
    4
    		O
     
    12
    18.1.33 Stibobetafite
    (Ca,Sb)
     
    2
    		(Ti,Nb,Ta)
     
    2
    		(O,OH)
     
    7
    18.1.34Bismutotantalite
    Bi(Ta,Nb)O
     
    4
    18.1.36Tantalite-(Mn)
    MnTa
     
    2
    		O
     
    6
    18.1.37Gerasimovskite
    (Mn,Ca)(Nb,Ti)
     
    5
    		O
     
    12
    		·9H
     
    2
    		O
    18.1.38Tapiolite-(Mn)
    (Mn,Fe)(Ta,Nb)
     
    2
    		O
     
    6
    18.1.39Columbite-(Mn)
    (Mn,Fe)(Nb,Ta)
     
    2
    		O
     
    6
    18.1.40Wodginite
    Mn(Sn,Ta)Ta
     
    2
    		O
     
    8
    18.1.41Ixiolite
    (Ta,Nb,Sn,Fe,Mn)
     
    4
    		O
     
    8
    18.1.42Columbite-(Fe)
    FeNb
     
    2
    		O
     
    6
    18.1.43Tantalite-(Fe)
    FeTa
     
    2
    		O
     
    6
    18.1.44Columbite
    (Fe,Mn)(Nb,Ta)
     
    2
    		O
     
    6
    18.1.45Tantalite
    (Fe,Mn)(Ta,Nb)
     
    2
    		O
     
    6
    18.1.46Tapiolite
    (Fe,Mn)(Ta,Nb)
     
    2
    		O
     
    6
    18.1.47Tapiolite-(Fe)
    (Fe,Mn)(Ta,Nb)
     
    2
    		O
     
    6
    18.1.48Columbite-(Mg)
    (Mg,Fe,Mn)(Nb,Ta)
     
    2
    		O
     
    6
    18.1.50Strüverite
    (Ti,Ta,Fe)O
     
    2
    18.1.51 Staringite
    (Fe,Mn)
     
    x
    		(Ta,Nb)
     
    2x
    		Sn
     
    6-3x
    		O
     
    12

    Other Names for Bismutomicrolite

    Synonyms:
    Westgrenite
    German names:
    BismutomicrolitBismutomikrolithWestgrenit
    Russian names:
    Висмутомикролит
    Spanish names:
    BismutomicrolitaWestgrenita

    Other Information

    Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

    References for Bismutomicrolite

    Reference List:von Knorring, O. and Mrose, M. E. (1963): Westgrenite [bismutomicrolite] and waylandite, two new bismuth minerals from Uganda. Geol. Soc. Amer. Spec. Paper 73, 256-257. - American Mineralogist 48, 215 (abstract).

    Erichsen de Oliveira, O., Rocha Baptista, N. and Baptista, A. (1970): Westgrenita [bismutomicrolite] no pegmatito de Tromba, Estado de Goiás. An. Acad. brasil. Ciénc. 42(1), 41-44 (in Portuguese).

    Hogarth, D. D. (1977): Classification and nomenclature of the pyrochlore group. American Mineralogist 62, 403-410, esp. 408.

    Anthony, J.W., Bideaux, R.A., Bladh, K.W., and Nichols, M.C. (1997) Handbook of Mineralogy, Volume III. Halides, Hydroxides, Oxides. Mineral Data Publishing, Tucson, AZ, 628pp.: 63.

    Internet Links for Bismutomicrolite

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  • Look for Bismutomicrolite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Bismutomicrolite in the Natural History Museum (London) online catalogue
  • Bismutomicrolite details from Handbook of Mineralogy (PDF)
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    Localities for Bismutomicrolite

    Hide Locality List
    The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Argentina
     
    • Salta
      • Nevados de Palermo
        • El Quemado District
    		Galliski et al. (2001) Bismutotantalite from northwestern Argentina: description and crystal structure. Can. Min. Vol. 39, pp. 103-110.
    Brazil
     
    • Central-West Region
      • Goiás
        • Trombas
    		Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 63
    • Northeast Region
      • Paraíba
        • Junco do Seridó
    		Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 63
      • Rio Grande do Norte
        • Seridó Oriental
          • Carnaúba dos Dantas
            • Ermo
    		Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 63
          • Equador
    Canada
     
    • Ontario
      • Kenora District
        • Separation Rapids
    		Tindle, A.G. & F.W.Breaks: "Oxide minerals of the Separation Rapids rare-element granitic pegmatite group, northwestern Ontario": Can. Min. 36: 609-635(1998)
    China
     
    • Xinjiang (Xinjiang-Uygur) Autonomous Region
      • Yili Hasake (Ili Kazakh) Autonomous Prefecture
        • Aletai (Altay) Prefecture
          • Fuyun Co.
    		http://www.smartminerals.com/cina2004/art_China_localities.htm
    Madagascar
     
    • Fianarantsoa Province
      • Amoron'i Mania Region
        • Ambatofinandrahana Department
    		Pers.com Roy Kristiansen 1996, XRD analysis Smithsonian Institution, USA 1974
    Russia
     
    • Eastern-Siberian Region
      • Transbaikalia (Zabaykalye)
        • Chitinskaya Oblast'
          • Krasny Chikoy
            • Malkhan pegmatite field (Malchan)
    		[Lapis 1993:1 p13-15]
    • Urals Region
      • Central Urals
        • Rezh District
          • Lipovka pegmatite field
    Uganda
     
    • Wakiso District
      • Busiiro Co. (Bushiro Co.)
    		Am Min 62 (1977), 403; HB3 (1997)
    USA
     
    • Wisconsin
      • Jefferson Co.
        • Waterloo
    		Buchholz, T.W., Falster, A.U., and Simmons, WmB. (2007) 34th Rochester Mineralogical Symposium, Contributed Papers.
    Mineral and/or Locality
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