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About ThoreauliteHide

Jacques Thoreau (1885-1973)
Brown to yellow
Adamantine, Resinous
5½ - 6
Specific Gravity:
7.6 - 7.9
Crystal System:
Member of:
Named in 1933 by Henri Buttgenbach in honor of Jacques Thoreau [September 27, 1886 Brussels, Belgium - January 11, 1973 Kessel-Lo, Belgium], Professor of Mineralogy, Université Catholique de Leuvain-UCL, Belgium.
Isostructural with:
Foordite-Thoreaulite Series.
Thoreaulite was first described by Buttgenbach (1933) from a pegmatite at the Manono Mine, Tanganyika, DR Congo.

Classification of ThoreauliteHide

Approved, 'Grandfathered' (first described prior to 1959)
First Published:

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
G : With large (+- medium-sized) cations; chains of edge-sharing octahedra
Dana 7th ed.:

3 : AB2O6

18 : Niobates and Tantalates
1 : Niobates and tantalates containing neither rare earths nor U

Physical Properties of ThoreauliteHide

Adamantine, Resinous
Brown to yellow
Yellow or greenish
5½ - 6 on Mohs scale
On {100}; on {011} imperfect.
7.6 - 7.9 g/cm3 (Measured)    

Optical Data of ThoreauliteHide

Biaxial (+)
RI values:
nα = 2.390 nβ = 2.420 nγ = 2.520
Measured: 25° to 35°, Calculated: 60°
On {100} cleavages = 0.039.
Max Birefringence:
δ = 0.130
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
Very High
r < v

Chemical Properties of ThoreauliteHide

IMA Formula:
Idealised Formula:

Crystallography of ThoreauliteHide

Crystal System:
Cell Parameters:
a = 17.14 Å, b = 4.86 Å, c = 5.54 Å
β = 91°
a:b:c = 3.527 : 1 : 1.14
Unit Cell V:
461.41 ų (Calculated from Unit Cell)
Crystals rough, prismatic [001].
Lamellar twins, with composition face {010}.

Type Occurrence of ThoreauliteHide

Geological Setting of Type Material:
Buttgenbach, H. (1933) La thoreaulite, nouvelle espèce minérale. Annales de la Société Géologique de Belgique 56: 327-331

Synonyms of ThoreauliteHide

Other Language Names for ThoreauliteHide

Simplified Chinese:钽锡矿

Relationship of Thoreaulite to other SpeciesHide

Member of:
Other Members of this group:
FoorditeSn2+(Nb,Ta)2O6Mon. 2/m : B2/b
Forms a series with:

Common AssociatesHide

Associated Minerals Based on Photo Data:
Cesplumtantite2 photos of Thoreaulite associated with Cesplumtantite on mindat.org.
Lithiotantite1 photo of Thoreaulite associated with Lithiotantite on mindat.org.
Cassiterite1 photo of Thoreaulite associated with Cassiterite on mindat.org.
Albite1 photo of Thoreaulite associated with Albite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

4.DG.05Euxenite-(Y)(Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6Orth. mmm (2/m 2/m 2/m)
4.DG.05Fersmite(Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DG.05Kobeite-(Y)(REE,Fe,U)3 Zr(Ti,Nb)3 O12
4.DG.05Loranskite-(Y)(Y,Ce,Ca)ZrTaO6 (?)
4.DG.05Polycrase-(Y)Y(Ti,Nb)2(O,OH)6Orth. mmm (2/m 2/m 2/m)
4.DG.05Uranopolycrase(U4+,Y)(Ti,Nb)2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DG.10Fergusonite-(Y)-βYNbO4Mon. 2/m
4.DG.15FoorditeSn2+(Nb,Ta)2O6Mon. 2/m : B2/b
4.DG.20RaspitePb(WO4)Mon. 2/m : P21/b

Related Minerals - Dana Grouping (8th Ed.)Hide,Ta)2O6Mon. 2/m : B2/b

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

18.1.2LueshiteNaNbO3Orth. mmm (2/m 2/m 2/m)
18.1.4FranconiteNa(Nb2O5)(OH) · 3H2OMon.
18.1.7Rankamaite(Na,K)3(Ta,Nb,Al)11(O,OH)31Orth. mmm (2/m 2/m 2/m) : Cmmm
18.1.8Hydropyrochlore(H2O,□)2Nb2(O,OH)6(H2O)Iso. m3m (4/m 3 2/m) : Fd3m
18.1.10RynersoniteCaTa2O6Orth. mmm (2/m 2/m 2/m)
18.1.11Microlite GroupA2-mTa2X6-wZ-nIso. m3m (4/m 3 2/m) : Fd3m
18.1.12BelyankiniteCa1-2(Ti,Nb)5O12 · 9H2O (?)Amor.
18.1.13LatrappiteCa2NbFe3+O6Orth. mmm (2/m 2/m 2/m) : Pnma
18.1.14Hochelagaite(Ca,Na,Sr)(Nb,Ti,Si,Al)4O11 · 8H2OMon.
18.1.15Bariomicrolite (of Hogarth 1977)Iso. m3m (4/m 3 2/m) : Fd3m
18.1.16ParabariomicroliteBaTa4O10(OH)2 · 2H2OTrig.
18.1.17Bariopyrochlore (of Hogarth 1977)A2Nb2(O,OH)6ZIso. m3m (4/m 3 2/m) : Fd3m
18.1.18AlumotantiteAlTaO4Orth. mmm (2/m 2/m 2/m) : Pbcn
18.1.19SimpsoniteAl4(Ta,Nb)3O13(OH,F)Trig. 3 : P3
18.1.22Stannomicrolite (of Hogarth 1977)
18.1.23FoorditeSn2+(Nb,Ta)2O6Mon. 2/m : B2/b
18.1.25Plumbopyrochlore (of Skorobogatova et al.)A2Nb2(O,OH)6Z
18.1.26Plumbomicrolite (of Hogarth 1977)
18.1.27StibiocolumbiteSb(Nb,Ta)O4Orth. mm2
18.1.28StibiotantaliteSb(Ta,Nb)O4Orth. mm2
18.1.31Stibiomicrolite (of Groat et al.)
18.1.35Bismutomicrolite (of Hogarth 1977)Iso. m3m (4/m 3 2/m) : Fd3m
18.1.36Tantalite-(Mn)Mn2+Ta2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
18.1.37Gerasimovskite(Mn,Ca)(Nb,Ti)5O12 · 9H2O
18.1.38Tapiolite-(Mn)(Mn,Fe)(Ta,Nb)2O6Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
18.1.39Columbite-(Mn)Mn2+Nb2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
18.1.42Columbite-(Fe)Fe2+Nb2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
18.1.43Tantalite-(Fe)Fe2+Ta2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
18.1.44ColumbiteOrth. mmm (2/m 2/m 2/m) : Pbcn
18.1.46Tapiolite(Fe,Mn)(Ta,Nb)2O6Tet. 4/mmm (4/m 2/m 2/m)
18.1.47Tapiolite-(Fe)(Fe,Mn)(Ta,Nb)2O6Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
18.1.51 Staringite(Fe,Mn)x(Ta,Nb)2xSn6-3xO12

Other InformationHide

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

References for ThoreauliteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Buttgenbach, H.(1933) La thoreaulite, nouvelle espéce minérale. Annales de la Société géologique de Belgique. 56: 327-328
American Mineralogist (1934): 19: 236.
Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged: 802.
Melon, J. & Toussaint, J. (1950) La thoreaulite de Kubitaka (Punia, Maniema, Congo Belge) et la crystallographie de la thoreaulite. Annales de la Société géologique de Belgique. 74: B25-32
American Mineralogist (1970): 55: 367-377.
American Mineralogist (1974): 59: 1026-1039.
Canadian Mineralogist (1988): 26: 899-903. (structure {Foordite}).

Internet Links for ThoreauliteHide

Localities for ThoreauliteHide

This 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.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Minas Gerais
    • Itinga
      • Monte Belo
[MinRec 12:74]; Daniel Atencio, Reynaldo R. Contreira Fo., Stuart J. Mills, Jose M.V. Coutinho, Sara B. Honorato, Alejandro P. Ayala, Javier Ellena, and Marcelo B. de Andrade (2011) Rankamaite from the Urubu pegmatite, Itinga, Minas Gerais, Brazil: crystal chemistry and Rietveld refinement. Am. Mineral. 96, 1455–1460.
  • Heilongjiang
    • Hegang
      • Luobei Co.
Deshi Lu (1993): Geology and Prospecting 29(6), 8-12
DR Congo
  • Maniema
Henri Buttgenbach (1947) Les minéraux de Belgique et du Congo belge
Uher, P., Cerny, P., & Chapman, R. (2008). Foordite-thoreaulite, Sn2+ Nb2O6Sn2+ Ta2O6: compositional variations and alteration products. European Journal of Mineralogy, 20(4), 501-516.
  • North Kivu
Vik Vanrusselt photo & specimen (Ex Rik Dillen specimen)
  • Tanganyika
Buttgenbach, H.(1933): La thoreaulite, nouvelle espéce minérale. Annales de la Société géologique de Belgique. 56: 327-328; Dewaele, S., Hulsbosch, N., Cryns, Y., Boyce, A., Burgess, R., & Muchez, P. (2016). Geological setting and timing of the world-class Sn, Nb–Ta and Li mineralization of Manono-Kitotolo (Katanga, Democratic Republic of Congo). Ore Geology Reviews, 72, 373-390.
  • East Kazakhstan
    • Kalba Range
      • Irtysh River
Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
    • Ulan
Voloshin, A.V., Pakomovskii, Ya.A., Stepanov, V.I., Tyusheva, F.N. (1983): Lithiotantite, Li,(Ta,Nb)3O8, a new mineral from granite pegmatites of Eastern Kazakhstan. Mineralogiceskij Zhurnal, 5(1), 91-95. Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
  • Western Province
    • Kabaya District
Ann. Soc. Geol. Belgique, Vol. 73, No. 8, p. 213-218, 1950.
    • Ngororero District
      • Gatumba
Bertossa, A. (1968) Inventaire des minéraux du Rwanda. Bulletin du Service Géologique de Rwanda: 4: 25-45.; Daltry, V.D.C. and von Knorring, O. (1998) Type-mineralogy of Rwanda with particular reference to the Buranga pegmatite. Geologica Belgica: 1: 9-15.
Mineral and/or Locality  
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