Sigloite
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About Sigloite

Siglo XX Mine, underground mining scene, ca. 1910
Siglo Veinte Mine, Llallagua, Rafael Bustillo Province, Potosí Department, Bolivia
Siglo Veinte Mine, Llallagua, Rafael Bustillo Province, Potosí Department, Bolivia
Formula:
Fe3+Al2(PO4)2(OH)3 · 7H2O
Colour:
Light brown, straw-yellow
Hardness:
3
Crystal System:
Triclinic
Member of:
Name:
Named after its discovery locality, the Siglo Veinte Mine (Siglo XX Mine), Llallagua, Bustillos Province, Potosí Department, Bolivia.
This page provides mineralogical data about Sigloite.
Classification of Sigloite
Approved
7/D.10-40
8.DC.30
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
42.11.14.3
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
19.14.26
19 : Phosphates
14 : Phosphates of Fe and other metals
19 : Phosphates
14 : Phosphates of Fe and other metals
Pronounciation of Sigloite
Pronounciation:
Play | Recorded by | Country |
---|---|---|
Jolyon & Katya Ralph | United Kingdom |
Physical Properties of Sigloite
Colour:
Light brown, straw-yellow
Hardness:
3 on Mohs scale
Optical Data of Sigloite
Type:
Biaxial (+)
RI values:
nα = 1.563 nβ = 1.586 nγ = 1.619
2V:
Measured: 76° , Calculated: 82°
Max Birefringence:
δ = 0.056

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:
Moderate
Dispersion:
strong
Chemical Properties of Sigloite
Formula:
Fe3+Al2(PO4)2(OH)3 · 7H2O
Crystallography of Sigloite
Crystal System:
Triclinic
Cell Parameters:
a = 5.26 Å, b = 10.52 Å, c = 7.06 Å
α = 106.97°, β = 111.5°, γ = 69.5°
α = 106.97°, β = 111.5°, γ = 69.5°
Ratio:
a:b:c = 0.5 : 1 : 0.671
Unit Cell V:
334.42 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction
Image Loading
Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Type Occurrence of Sigloite
Synonyms of Sigloite
Other Language Names for Sigloite
Relationship of Sigloite to other Species
Member of:
Other Members of this group:
Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Gordonite | MgAl2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Kummerite | Mn2+Fe3+Al(PO4)2(OH)2·8H2O | Tric. 1 : P1 |
Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. |
Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O | Tric. |
Common Associates
Associated Minerals Based on Photo Data:
Paravauxite | 349 photos of Sigloite associated with Paravauxite on mindat.org. |
Vauxite | 75 photos of Sigloite associated with Vauxite on mindat.org. |
Metavauxite | 69 photos of Sigloite associated with Metavauxite on mindat.org. |
Wavellite | 30 photos of Sigloite associated with Wavellite on mindat.org. |
Pyrite | 20 photos of Sigloite associated with Pyrite on mindat.org. |
Quartz | 17 photos of Sigloite associated with Quartz on mindat.org. |
Franckeite | 14 photos of Sigloite associated with Franckeite on mindat.org. |
Greenockite | 8 photos of Sigloite associated with Greenockite on mindat.org. |
Römerite | 5 photos of Sigloite associated with Römerite on mindat.org. |
Related Minerals - Nickel-Strunz Grouping
8.DC.05 | Nissonite | Cu2Mg2(PO4)2(OH)2 · 5H2O | Mon. |
8.DC.07 | Euchroite | Cu2(AsO4)(OH) · 3H2O | Orth. 2 2 2 : P21 21 21 |
8.DC.10 | Legrandite | Zn2(AsO4)(OH) · H2O | Mon. 2/m : P21/b |
8.DC.12 | Strashimirite | Cu8(AsO4)4(OH)4 · 5H2O | Mon. |
8.DC.15 | Arthurite | CuFe3+2(AsO4)2(OH)2 · 4H2O | Mon. |
8.DC.15 | Earlshannonite | Mn2+Fe3+2(PO4)2(OH)2 · 4H2O | Mon. |
8.DC.15 | Ojuelaite | ZnFe3+2(AsO4)2(OH)2 · 4H2O | Mon. |
8.DC.15 | Whitmoreite | Fe2+Fe3+2(PO4)2(OH)2 · 4H2O | Mon. 2/m : P21/b |
8.DC.15 | Cobaltarthurite | (Co,Mg)Fe3+2(AsO4)2(OH)2 · 4H2O | Mon. 2/m : P21/b |
8.DC.15 | Bendadaite | Fe2+Fe3+2(AsO4)2(OH)2 · 4H2O | Mon. 2/m : P21/b |
8.DC.15 | Kunatite | CuFe3+2(PO4)2(OH)2 · 4H2O | Mon. 2/m : P21/b |
8.DC.15 | UKI-2006-(PO:FeHZn) | ZnFe3+2(PO4)2(OH)2 · 4H2O | Mon. |
8.DC.15 | UKI-2006-(PO:AlCuFeH) | Fe2+Al3+2(PO4)2(OH)2 · 4H2O | |
8.DC.17 | Kleemanite | ZnAl2(PO4)2(OH)2 · 3H2O | Mon. |
8.DC.20 | Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O | Mon. 2/m : P2/b |
8.DC.20 | Coralloite | Mn2+Mn3+2(AsO4)2(OH)2 · 4H2O | Tric. 1 : P1 |
8.DC.22 | Kovdorskite | Mg2(PO4)(OH) · 3H2O | Mon. |
8.DC.25 | Ferristrunzite | Fe3+Fe3+2(PO4)2(OH)3 · 5H2O | Tric. |
8.DC.25 | Ferrostrunzite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O | Tric. |
8.DC.25 | Metavauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Mon. 2/m : P21/b |
8.DC.25 | Metavivianite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
8.DC.25 | Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
8.DC.27 | Beraunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O | Mon. 2/m : B2/b |
8.DC.30 | Gordonite | MgAl2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. |
8.DC.30 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Mon. 2/m : P21/b |
8.DC.30 | Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O | Tric. |
8.DC.30 | Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Maghrebite | MgAl2(AsO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
8.DC.30 | Nordgauite | MnAl2(PO4)2(F,OH)2 · 5H2O | Tric. 1 : P1 |
8.DC.32 | Tinticite | Fe3+5.34(PO4)3.62(VO4)0.38(OH)4 · 6.7H2O | Tric. 1 : P1 |
8.DC.35 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
8.DC.37 | Vantasselite | Al4(PO4)3(OH)3 · 9H2O | Orth. |
8.DC.40 | Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O | Hex. 6/m : P63/m |
8.DC.45 | Gormanite | (Fe2+,Mg)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O | Tric. |
8.DC.45 | Souzalite | (Mg,Fe2+)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O | Tric. |
8.DC.47 | Kingite | Al3(PO4)2F2(OH) · 7H2O | Tric. |
8.DC.50 | Wavellite | Al3(PO4)2(OH,F)3 · 5H2O | Orth. mmm (2/m 2/m 2/m) |
8.DC.50 | Allanpringite | Fe3+3(PO4)2(OH)3 · 5H2O | Mon. 2/m : P21/m |
8.DC.52 | Kribergite | Al5(PO4)3(SO4)(OH)4 · 4H2O | Tric. 1 : P1 |
8.DC.55 | Mapimite | Zn2Fe3+3(AsO4)3(OH)4 · 10H2O | Mon. |
8.DC.57 | Ogdensburgite | Ca2Fe3+4(Zn,Mn2+)(AsO4)4(OH)6 · 6H2O | Orth. mmm (2/m 2/m 2/m) : Cmmm |
8.DC.60 | Nevadaite | (Cu2+,Al,V3+)6Al8(PO4)8F8(OH)2 · 22H2O | Orth. mmm (2/m 2/m 2/m) |
8.DC.60 | Cloncurryite | Cu0.5(VO)0.5Al2(PO4)2F2 · 5H2O | Mon. 2/m : P21/b |
Related Minerals - Dana Grouping (8th Ed.)
42.11.14.1 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
42.11.14.2 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
42.11.14.4 | Gordonite | MgAl2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
42.11.14.5 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. |
Related Minerals - Hey's Chemical Index of Minerals Grouping
19.14.1 | Cyrilovite | NaFe3+3(PO4)2(OH)4 · 2H2O | Tet. 4 2 2 : P41 21 2 |
19.14.2 | Kidwellite | NaFe3+9+x(PO4)6(OH)11 · 3H2O, x = 0.33 | Mon. 2/m : P2/b |
19.14.3 | Rosemaryite | (Na,Ca,Mn)(Mn,Fe2+)(Fe3+,Mg)Al(PO4)3 | Mon. 2/m : P21/b |
19.14.4 | Wyllieite | (Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3 | Mon. 2/m |
19.14.5 | Ferrowyllieite | (Na,Ca,Mn)(Fe,Mn)(Fe,Fe,Mg)Al(PO4)3 | Mon. 2/m : P21/b |
19.14.6 | Natrodufrénite | NaFe2+Fe3+5(PO4)4(OH)6 · 2H2O | Mon. |
19.14.7 | Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O | Mon. 2/m : P21/b |
19.14.8 | Spheniscidite | (NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2O | Mon. |
19.14.9 | Burangaite | NaFe2+Al5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
19.14.10 | Satterlyite | (Fe2+,Mg,Fe)12(PO4)5(PO3OH)(OH,O)6 | Trig. 3m (3 2/m) : P3 1m |
19.14.11 | Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O | Tric. |
19.14.12 | Garyansellite | (Mg,Fe)3(PO4)2(OH,O) · 1.5H2O | Orth. mmm (2/m 2/m 2/m) |
19.14.13 | Thadeuite | Ca(Mg,Fe2+)3(PO4)2(OH,F)2 | Orth. 2 2 2 : C2 2 21 |
19.14.14 | Anapaite | Ca2Fe2+(PO4)2 · 4H2O | Tric. 1 : P1 |
19.14.15 | Xanthoxenite | Ca4Fe3+2(PO4)4(OH)2 · 3H2O | Tric. 1 : P1 |
19.14.16 | Calcioferrite | Ca2Fe3+2(PO4)3(OH) · 7H2O | Mon. 2/m : B2/b |
19.14.17 | Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O | Mon. 2/m : B2/b |
19.14.18 | Mélonjosephite | CaFe2+Fe3+(PO4)2(OH) | |
19.14.19 | Delvauxite | CaFe4(PO4,SO4)2(OH)8 · 4-6H2O not confirmed · | Amor. |
19.14.20 | Collinsite | Ca2(Mg,Fe2+)(PO4)2 · 2H2O | Tric. 1 : P1 |
19.14.21 | Segelerite | Ca2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2O | Orth. mmm (2/m 2/m 2/m) : Pcca |
19.14.22 | Kingsmountite | Ca4(Fe2+,Mn2+)Al4(PO4)6(OH)4 · 12H2O | Mon. 2 : B2 |
19.14.23 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
19.14.24 | Metavauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Mon. 2/m : P21/b |
19.14.25 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
19.14.27 | Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O | Hex. 6/m : P63/m |
19.14.28 | Koninckite | Fe3+PO4 · 3H2O | Tet. |
19.14.29 | Lazulite | (Mg,Fe2+)Al2(PO4)2(OH)2 | Mon. 2/m : P21/b |
19.14.30 | Scorzalite | Fe2+Al2(PO4)2(OH)2 | Mon. 2/m : P21/b |
19.14.31 | Souzalite | (Mg,Fe2+)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O | Tric. |
19.14.32 | Gormanite | (Fe2+,Mg)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O | Tric. |
19.14.33 | Zaïrite | BiFe3+3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
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 Sigloite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
American Mineralogist (1962): 47: 1-8.
Mineralogy and Petrology (1988): 38: 201-211.
American Mineralogist (1989): 74: 1404.
Internet Links for Sigloite
mindat.org URL:
https://www.mindat.org/min-3657.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
Localities for Sigloite
Locality List




All localities listed without proper references should be considered as questionable.
Bolivia (TL) | |
| Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 973; American Mineralogist (1962): 47: 1-8; Mineralogical Record: 32: 474. |
France | |
| Lheur, C. & Meisser, N. (2013): Nouveautés à Fumade (Tarn): clinobisvanite, meurigite-K, sigloite et sudoite. Le Règne Minéral, 110, 52-53. |
USA | |
| Josef Vajdak (2002) Mineral News, 18, #1, 6. |
| Kenny Gay Collection |
Siglo Veinte Mine, Llallagua, Rafael Bustillo Province, Potosí Department, Bolivia