Rankamaite
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About Rankamaite
Formula:
(Na,K)3(Ta,Nb,Al)11(O,OH)31
Colour:
Creamy-white
Hardness:
3 - 4
Crystal System:
Orthorhombic
Name:
Named after Professor Kalervo Rankama (1913–1995), Finnish geochemist, University of Helsinki, Helsinki, Finland.
This page provides mineralogical data about Rankamaite.
Classification of Rankamaite
Approved
4/D.27-40
4.DM.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
M : With large (+- medium-sized) cations; unclassified
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
M : With large (+- medium-sized) cations; unclassified
8.7.6.1
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
7 : Miscellaneous
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
7 : Miscellaneous
18.1.7
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 Rankamaite
Colour:
Creamy-white
Hardness:
3 - 4 on Mohs scale
Optical Data of Rankamaite
Type:
Biaxial
Dispersion:
r < v extreme
Chemical Properties of Rankamaite
Formula:
(Na,K)3(Ta,Nb,Al)11(O,OH)31
Crystallography of Rankamaite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Cmmm
Setting:
Cmmm
Cell Parameters:
a = 17.224(3) Å, b = 17.687(3) Å, c = 3.9361(7) Å
α = 90°, β = 90°, γ = 90°
α = 90°, β = 90°, γ = 90°
Ratio:
a:b:c = 0.974 : 1 : 0.223
Unit Cell V:
1199.1 ų
Z:
2
Comment:
Atencio et al. (2011)
Type Occurrence of Rankamaite
Synonyms of Rankamaite
Other Language Names for Rankamaite
German:Rankamait
Spanish:Rankamaita
Common Associates
Associated Minerals Based on Photo Data:
3 photos of Rankamaite associated with Cassiterite | SnO2 |
3 photos of Rankamaite associated with Simpsonite | Al4Ta3O13(OH) |
2 photos of Rankamaite associated with Tantalite-(Mn) | Mn2+Ta2O6 |
1 photo of Rankamaite associated with Wodginite | Mn2+Sn4+Ta2O8 |
1 photo of Rankamaite associated with Tourmaline | A(D3)G6(Si6O18)(BO3)3X3Z |
Related Minerals - Nickel-Strunz Grouping
4.DM.05 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 | Orth. |
4.DM.15 | Cesplumtantite | (Cs,Na)2(Pb,Sb3+)3Ta8O24 | Tet. |
4.DM.20 | Eyselite | Fe3+Ge4+3O7(OH) | Orth. |
4.DM.25 | Kuranakhite | PbMn4+Te6+O6 | Orth. |
Related Minerals - Dana Grouping (8th Ed.)
8.7.6.2 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 | Orth. |
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. |
18.1.8 | 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 | A2-mTa2X6-wZ-n | 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 | Al4Ta3O13(OH) | Trig. 3 : P3 |
18.1.20 | Sosedkoite | (K,Na)5Al2(Ta,Nb)22O60 | Orth. |
18.1.21 | Thoreaulite | (Sn2+,Pb)(Ta,Nb)2O6 | Mon. |
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) | Mn2+Ta2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.37 | Gerasimovskite | (Mn,Ca)(Nb,Ti)5O12 · 9H2O | Amor. |
18.1.38 | Tapiolite-(Mn) | Mn2+Ta2O6 | Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm |
18.1.39 | Columbite-(Mn) | Mn2+Nb2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.40 | Wodginite | Mn2+Sn4+Ta2O8 | Mon. 2/m : B2/b |
18.1.41 | Ixiolite | (Ta,Nb,Sn,Fe,Mn)4O8 | Orth. |
18.1.42 | Columbite-(Fe) | Fe2+Nb2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
18.1.43 | Tantalite-(Fe) | Fe2+Ta2O6 | 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) | Fe2+Ta2O6 | 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 Rankamaite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
von Knorring, O., Vorma, A., Nixon, P.H. (1969): Rankamaite, a new tantalum mineral from Kivu, Congo. Bulletin of the Geological Society of Finland 41, 47-56.
American Mineralogist (1970): 55: 1814 (Abs.).
Mineralogicheskii Zhurnal (1984): 6: 42-55.
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.
Internet Links for Rankamaite
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https://www.mindat.org/min-3362.html
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Localities for Rankamaite
Locality List




All localities listed without proper references should be considered as questionable.
Brazil | |
| 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. |
DR Congo | |
| Bul. Geol. Soc. Fin. 41 (1969), 47; V.D.C. Daltry (1992) The Type Mineralogy Of Africa : Zaire pp 33-62 |
Safiannikoff, A. and van Wambeke, L. (1961): Sur un terme plombifere du groupe pyrochlore-microlite. Bulletin de la Société Francaise de Minéralogie et de Cristallographie 84: 382-384 | |
| Voloshin A.V., Pakhomovskii Ya.A. (1988) Mineralogy of tantalum and niobium in rare-metal pegmatites, - Leningrad, Nauka, p. 240 (in Rus.) |
Kazakhstan | |
| A.V. Voloshin analytical data |
| 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 |
Mumba, Osso, Masisi Territory, North Kivu, DR Congo