Thoreaulite
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Formula:
(Sn2+,Pb)(Ta,Nb)2O6
Colour:
Brown to yellow
Lustre:
Adamantine, Resinous
Hardness:
5½ - 6
Specific Gravity:
7.6 - 7.9
Crystal System:
Monoclinic
Member of:
Name:
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:
Classification of Thoreaulite
Approved, 'Grandfathered' (first described prior to 1959)
4/D.29-20
4.DG.15
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
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.:
8.3.10.1
8.3.10.1
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
3 : AB2O6
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
3 : AB2O6
18.1.21
18 : Niobates and Tantalates
1 : Niobates and tantalates containing neither rare earths nor U
18 : Niobates and Tantalates
1 : Niobates and tantalates containing neither rare earths nor U
Physical Properties of Thoreaulite
Adamantine, Resinous
Colour:
Brown to yellow
Streak:
Yellow or greenish
Hardness:
5½ - 6 on Mohs scale
Cleavage:
Perfect
On {100}; on {011} imperfect.
On {100}; on {011} imperfect.
Density:
7.6 - 7.9 g/cm3 (Measured)
Optical Data of Thoreaulite
Type:
Biaxial (+)
RI values:
nα = 2.390 nβ = 2.420 nγ = 2.520
2V:
Measured: 25° to 35°, Calculated: 60°
Birefringence:
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.
and does not take into account mineral colouration.
Surface Relief:
Very High
Dispersion:
r < v
Chemical Properties of Thoreaulite
Formula:
(Sn2+,Pb)(Ta,Nb)2O6
IMA Formula:
Sn2+Ta2O6
Idealised Formula:
Sn2+Ta2O6
Elements listed:
Crystallography of Thoreaulite
Crystal System:
Monoclinic
Cell Parameters:
a = 17.14 Å, b = 4.86 Å, c = 5.54 Å
β = 91°
β = 91°
Ratio:
a:b:c = 3.527 : 1 : 1.14
Unit Cell V:
461.41 ų (Calculated from Unit Cell)
Morphology:
Crystals rough, prismatic [001].
Twinning:
Lamellar twins, with composition face {010}.
Type Occurrence of Thoreaulite
Synonyms of Thoreaulite
Other Language Names for Thoreaulite
Relationship of Thoreaulite to other Species
Common Associates
Associated Minerals Based on Photo Data:
Cesplumtantite | 2 photos of Thoreaulite associated with Cesplumtantite on mindat.org. |
Lithiotantite | 1 photo of Thoreaulite associated with Lithiotantite on mindat.org. |
Cassiterite | 1 photo of Thoreaulite associated with Cassiterite on mindat.org. |
Albite | 1 photo of Thoreaulite associated with Albite on mindat.org. |
Related Minerals - Nickel-Strunz Grouping
4.DG.05 | Euxenite-(Y) | (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 | Orth. mmm (2/m 2/m 2/m) |
4.DG.05 | Fersmite | (Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
4.DG.05 | Kobeite-(Y) | (REE,Fe,U)3 Zr(Ti,Nb)3 O12 | |
4.DG.05 | Loranskite-(Y) | (Y,Ce,Ca)ZrTaO6 (?) | |
4.DG.05 | Polycrase-(Y) | Y(Ti,Nb)2(O,OH)6 | Orth. mmm (2/m 2/m 2/m) |
4.DG.05 | Tanteuxenite-(Y) | Y(Ta,Nb,Ti)2(O,OH)6 | |
4.DG.05 | Uranopolycrase | (U4+,Y)(Ti,Nb)2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
4.DG.05 | Yttrocrasite-(Y) | (Y,Th,Ca,U)(Ti,Fe)2(O,OH)6 | Amor. |
4.DG.10 | Fergusonite-(Y)-β | YNbO4 | Mon. 2/m |
4.DG.10 | Fergusonite-(Nd)-β | (Nd,Ce)NbO4 | |
4.DG.10 | Fergusonite-(Ce)-β | (Ce,La,Nd)NbO4 | |
4.DG.10 | Yttrotantalite-(Y) | (Y,U4+,Fe2+)(Ta,Nb)(O,OH)4 | Orth. |
4.DG.10 | Beta-Fergusonite-(Nd) | (Nd,Ce)NbO4 | |
4.DG.15 | Foordite | Sn2+(Nb,Ta)2O6 | Mon. 2/m : B2/b |
4.DG.20 | Raspite | Pb(WO4) | Mon. 2/m : P21/b |
Related Minerals - Dana Grouping (8th Ed.)
8.3.10.2 | Foordite | Sn2+(Nb,Ta)2O6 | Mon. 2/m : B2/b |
Related Minerals - Hey's Chemical Index of Minerals Grouping
18.1.1 | Lithiotantite | LiTa3O8 | Mon. |
18.1.2 | Lueshite | NaNbO3 | Orth. mmm (2/m 2/m 2/m) |
18.1.3 | Natroniobite | NaNbO3 | Mon. |
18.1.4 | Franconite | Na(Nb2O5)(OH) · 3H2O | Mon. |
18.1.5 | Natrotantite | Na2Ta4O11 | Mon. |
18.1.6 | Irtyshite | Na2(Ta,Nb)4O11 | Hex. |
18.1.7 | Rankamaite | (Na,K)3(Ta,Nb,Al)11(O,OH)31 | Orth. mmm (2/m 2/m 2/m) : Cmmm |
18.1.8 | Hydropyrochlore | (H2O,□)2Nb2(O,OH)6(H2O) | Iso. m3m (4/m 3 2/m) : Fd3m |
18.1.9 | Calciotantite | CaTa4O11 | Hex. |
18.1.10 | Rynersonite | CaTa2O6 | Orth. mmm (2/m 2/m 2/m) |
18.1.11 | Microlite Group | Iso. m3m (4/m 3 2/m) : Fd3m | |
18.1.12 | Belyankinite | Ca1-2(Ti,Nb)5O12 · 9H2O (?) | Amor. |
18.1.13 | Latrappite | Ca2NbFe3+O6 | Orth. mmm (2/m 2/m 2/m) : Pnma |
18.1.14 | Hochelagaite | (Ca,Na,Sr)(Nb,Ti,Si,Al)4O11 · 8H2O | Mon. |
18.1.15 | Bariomicrolite (of Hogarth 1977) | Iso. m3m (4/m 3 2/m) : Fd3m | |
18.1.16 | Parabariomicrolite | BaTa4O10(OH)2 · 2H2O | Trig. |
18.1.17 | Bariopyrochlore (of Hogarth 1977) | A2Nb2(O,OH)6Z | Iso. m3m (4/m 3 2/m) : Fd3m |
18.1.18 | Alumotantite | AlTaO4 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.19 | Simpsonite | Al4(Ta,Nb)3O13(OH,F) | Trig. 3 : P3 |
18.1.20 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 | Orth. |
18.1.22 | Stannomicrolite (of Hogarth 1977) | ||
18.1.23 | Foordite | Sn2+(Nb,Ta)2O6 | Mon. 2/m : B2/b |
18.1.24 | Changbaiite | PbNb2O6 | Trig. |
18.1.25 | Plumbopyrochlore (of Skorobogatova et al.) | A2Nb2(O,OH)6Z | |
18.1.26 | Plumbomicrolite (of Hogarth 1977) | ||
18.1.27 | Stibiocolumbite | Sb(Nb,Ta)O4 | Orth. mm2 |
18.1.28 | Stibiotantalite | Sb(Ta,Nb)O4 | Orth. mm2 |
18.1.29 | Natrobistantite | Iso. | |
18.1.30 | Cesplumtantite | (Cs,Na)2(Pb,Sb3+)3Ta8O24 | Tet. |
18.1.31 | Stibiomicrolite (of Groat et al.) | ||
18.1.32 | Cesstibtantite | ||
18.1.34 | Bismutotantalite | Bi(Ta,Nb)O4 | Orth. |
18.1.35 | Bismutomicrolite (of Hogarth 1977) | Iso. m3m (4/m 3 2/m) : Fd3m | |
18.1.36 | Tantalite-(Mn) | MnTa2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.37 | Gerasimovskite | (Mn,Ca)(Nb,Ti)5O12 · 9H2O | |
18.1.38 | Tapiolite-(Mn) | (Mn,Fe)(Ta,Nb)2O6 | Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm |
18.1.39 | Columbite-(Mn) | (Mn,Fe)(Nb,Ta)2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.40 | Wodginite | Mn2+Sn4+Ta2O8 | Mon. |
18.1.41 | Ixiolite | (Ta,Nb,Sn,Fe,Mn)4O8 | Orth. |
18.1.42 | Columbite-(Fe) | FeNb2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.43 | Tantalite-(Fe) | FeTa2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.44 | Columbite | Orth. mmm (2/m 2/m 2/m) : Pbcn | |
18.1.45 | Tantalite | (Mn,Fe)(Ta,Nb)2O6 | |
18.1.46 | Tapiolite | (Fe,Mn)(Ta,Nb)2O6 | Tet. 4/mmm (4/m 2/m 2/m) |
18.1.47 | Tapiolite-(Fe) | (Fe,Mn)(Ta,Nb)2O6 | Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm |
18.1.48 | Columbite-(Mg) | (Mg,Fe,Mn)(Nb,Ta)2O6 | Orth. |
18.1.50 | Strüverite | (Ti,Ta,Fe)O2 | |
18.1.51 | Staringite | (Fe,Mn)x(Ta,Nb)2xSn6-3xO12 |
Other Information
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 Thoreaulite
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.
American Mineralogist (1970): 55: 367-377.
American Mineralogist (1974): 59: 1026-1039.
Canadian Mineralogist (1988): 26: 899-903. (structure {Foordite}).
Internet Links for Thoreaulite
mindat.org URL:
https://www.mindat.org/min-3943.html
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Localities for Thoreaulite
Locality List




All localities listed without proper references should be considered as questionable.
Brazil | |
| [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. |
China | |
| Deshi Lu (1993): Geology and Prospecting 29(6), 8-12 |
Democratic Republic of the Congo (TL) | |
| Buttgenbach, H.(1933): La thoreaulite, nouvelle espéce minérale. Annales de la Société géologique de Belgique. 56: 327-328 |
| 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. | |
| Vik Vanrusselt photo & specimen (Ex Rik Dillen specimen) |
Kazakhstan | |
| Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow |
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 | |
Rwanda | |
| 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. |
| Ann. Soc. Geol. Belgique, Vol. 73, No. 8, p. 213-218, 1950. |
Manono Mine, Katanga, Democratic Republic of the Congo