Fanfaniite
A valid IMA mineral species
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About Fanfaniite
Formula:
Ca4Mn2+Al4(PO4)6(OH)4 · 12H2O
Colour:
colorless
Crystal System:
Monoclinic
Member of:
Name:
The name honours Luca Fanfani (b. 1941, Florence, Italy), Mineralogical Institute, University of Cagliari, Italy, who structurally characterised a large number of phosphate minerals including montgomeryite.
Unique Identifiers
Mindat ID:
53148
Long-form identifier:
mindat:1:1:53148:1
IMA Classification of Fanfaniite
Approved
IMA Formula:
Ca4Mn2+Al4(PO4)6(OH)4·12H2O
Approval year:
2018
First published:
2019
Classification of Fanfaniite
8.DH.25
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ffa | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Fanfaniite
Transparency:
Transparent
Colour:
Colorless
Optical Data of Fanfaniite
Type:
Biaxial (-)
RI values:
nα = 1.573(2) nβ = 1.582(2) nγ = 1.585(2)
2V:
Measured: 57° (1)
Max. Birefringence:
δ = 0.012
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Pleochroism:
Not Visible
Chemistry of Fanfaniite
Mindat Formula:
Ca4Mn2+Al4(PO4)6(OH)4 · 12H2O
Element Weights:
Crystallography of Fanfaniite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 10.055(2) Å, b = 24.132(5) Å, c = 6.2590(10) Å
β = 91.35(3)°
β = 91.35(3)°
Ratio:
a:b:c = 0.417 : 1 : 0.259
Unit Cell V:
1,518.31 ų (Calculated from Unit Cell)
Comment:
updated from specimen from Hühnerkobel pegmatite, may be triclinic
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.14 Å | (33) |
| 5.13 Å | (97) |
| 3.137 Å | (28) |
| 2.938 Å | (100) |
| 2.817 Å | (19) |
| 2.618 Å | (70) |
| 2.249 Å | (25) |
| 1.740 Å | (22) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Type Occurrence of Fanfaniite
General Appearance of Type Material:
Radial aggregates up to 0.5 mm in diameter of colourless, transparent, thin blades, associated with whiteite-(CaMnMn). At Hagendorf-Süd, the mineral occurs as isolated very thin laths on the surface of fibrous spheroids of kayrobertsonite.
Place of Conservation of Type Material:
1) Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue numbers 66771 (Foote mine holotype) and 66772 (Foote mine cotype)
2) Museum Victoria, Australia
2) Museum Victoria, Australia
Geological Setting of Type Material:
oxidation of pegmatite phosphates.
Associated Minerals at Type Locality:
Synonyms of Fanfaniite
Other Language Names for Fanfaniite
Dutch:Fanfaniiet
German:Fanfaniit
Relationship of Fanfaniite to other Species
Member of:
Other Members of Montgomeryite Subgroup:
| Kingsmountite | Ca3Mn2+FeAl4(PO4)6(OH)4 · 12H2O | Tric. 1 : P1 |
| Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O | Mon. 2 : B2 |
Related Minerals - Strunz-mindat Grouping
| 8.DH. | Thebaite-(NH4) | (NH4)3Al(C2O4)(PO3OH)2(H2O) |
| 8.DH. | Whiteite-(MnMnMn) | Mn2+Mn2+Mn2+2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH. | Ammoniotinsleyite | (NH4)Al2(PO4)2(OH) · 2H2O |
| 8.DH. | Bergbauerite | (H2O)2Mn2(Fe2Ti)(PO4)4(OH)2(H2O)10 · 4H2O |
| 8.DH. | Dendoraite-(NH4) | (NH4)2NaAl(C2O4)(PO3OH)2(H2O)2 |
| 8.DH. | Rowleyite | [Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6 · n[H2O,Na,NH4,K,Cl] |
| 8.DH. | Hochleitnerite | Mn2Ti3(PO4)4O2(H2O)2 · 14H2O |
| 8.DH. | Whiteite-(CaMnFe) | CaMnFe2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.05 | Minyulite | KAl2(PO4)2F · 4H2O |
| 8.DH.10 | Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O |
| 8.DH.10 | Tinsleyite | KAl2(PO4)2(OH) · 2H2O |
| 8.DH.10 | Spheniscidite | (NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2O |
| 8.DH.15 | Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(NaMnMn) | {Na}{Mn2+}{(Mn2+,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(MnMnMg) | MnMnMg2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnZn) | {Ca}{Mn2+}{Zn2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnMg) | {Mn2+}{Mn2+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnFe) | {Mn2+}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | 'Jahnsite-(CaFeFe)' | {Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Rittmannite | {(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Keckite | CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O |
| 8.DH.15 | Jahnsite-(NaMnMg) | {(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | 'Jahnsite-(CaMgMg)' | {Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnZn) | {Mn2+}{Mn2+}{Zn2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMgMg) | CaMg3Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaFeMg) | {Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(MnFeMg) | {(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnMn) | {Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | 'Kaluginite' | (Mn2+,Ca)MgFe3+(PO4)2(OH) · 4H2O |
| 8.DH.15 | Jahnsite-(CaFeMg) | {Ca}{Fe2+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMnMn) | {Ca}{Mn2+}{Mn2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(NaFeMg) | {Na}{Fe3+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.20 | Segelerite | Ca2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2O |
| 8.DH.20 | Lun'okite | (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2OH · 4H2O |
| 8.DH.20 | Manganosegelerite | (Mn2+,Ca)(Mn2+,Fe2+,Mg)Fe3+(PO4)2(OH) · 4H2O |
| 8.DH.20 | Wilhelmvierlingite | CaMnFe3+(PO4)2(OH) · 2H2O |
| 8.DH.20 | Juonniite | CaMgSc(PO4)2(OH) · 4H2O |
| 8.DH.20 | Overite | CaMgAl(PO4)2(OH) · 4H2O |
| 8.DH.25 | Calcioferrite | Ca4MgFe3+4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Zodacite | Ca4Mn2+Fe3+4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Kingsmountite | Ca3Mn2+FeAl4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O |
| 8.DH.30 | Pararobertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Arseniosiderite | Ca2Fe3+3(AsO4)3O2 · 3H2O |
| 8.DH.30 | Sailaufite | (Ca,Na,◻)2Mn3+3(AsO4)2(CO3)O2 · 3H2O |
| 8.DH.30 | Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Kolfanite | Ca2Fe3+3O2(AsO4)3 · 2H2O |
| 8.DH.35 | Mantienneite | KMg2Al2Ti(PO4)4(OH)3 · 15H2O |
| 8.DH.35 | Sperlingite | (H2O)K(Mn2+Fe3+)(Al2Ti)(PO4)4[O(OH)] [(H2O)9(OH)] · 4H2O |
| 8.DH.35 | Paulkerrite | K(Mg,Mn2+)2(Fe3+,Al,Ti,Mg)2Ti(PO4)4(OH)3 · 15H2O |
| 8.DH.35 | Hydroxylbenyacarite | (H2O)2Mn2(Ti2Fe)(PO4)4[O(OH)](H2O)10 · 4H2O |
| 8.DH.35 | Macraeite | K(H2O)Mn2(Fe2Ti)(PO4)4[O(OH)](H2O)10 · 4H2O |
| 8.DH.35 | Benyacarite | (H2O)2Mn2Ti2Fe3+(PO4)4(OF)(H2O)10 · 4H2O |
| 8.DH.35 | Fluormacraeite | [(H2O)K]Mn2(Fe2Ti)(PO4)4(OF)(H2O)10 · 4H2O |
| 8.DH.40 | Xanthoxenite | Ca4Fe3+2(PO4)4(OH)2 · 3H2O |
| 8.DH.45 | Mahnertite | NaCu3(AsO4)2Cl · 5H2O |
| 8.DH.50 | Andyrobertsite | KCdCu5(AsO4)4(H2AsO4) · 2H2O |
| 8.DH.50 | Calcioandyrobertsite | KCaCu5(AsO4)4(H2AsO4) · 2H2O |
| 8.DH.55 | Englishite | K3Na2Ca10Al15(PO4)21(OH)7 · 26H2O |
| 8.DH.60 | Bouazzerite | Bi6(Mg,Co)11Fe3+14(AsO4)18(OH)4O12 · 86H2O |
| 8.DH.65 | Galliskiite | Ca4Al2(PO4)2F8 · 5H2O |
| 8.DH.70 | Joteite | Ca2CuAl(AsO4)[AsO3(OH)]2(OH)2 · 5H2O |
| 8.DH.75 | Kampelite | Ba6Mg3Sc8(PO4)12(OH)6 · 7H2O |
| 8.DH.80 | Kapundaite | NaCaFe4(PO4)4(OH)3 · 5H2O |
| 8.DH.85 | Vaniniite | Ca2Mn2+3Mn3+2O2(AsO4)4 · 2H2O |
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.
Internet Links for Fanfaniite
mindat.org URL:
https://www.mindat.org/min-53148.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Fanfaniite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2018) CNMNC Newsletter 45, New minerals and nomenclature modifications approved in 2018. Mineralogical Magazine, 82 (5) 1225-1232 doi:10.1180/mgm.2018.160
Grey, Ian E., Kampf, Anthony R., Smith, Jason B., MacRae, Colin M., Keck, Erich (2019) Fanfaniite, Ca4Mn2+Al4(PO4)6(OH,F)4·12H2O, a new mineral with a montgomeryite-type structure. European Journal of Mineralogy, 31 (3) 647-652 doi:10.1127/ejm/2019/0031-2857
Grey, Ian E.; Bird, Stephanie; MacRae, Colin M.; Rewitzer, Christian; Hochleitner, Rupert (2026) Structural ordering in calcioferrite-group minerals. Refinement of the crystal structure of fanfaniite from the Hühnerkobel pegmatite, Bavaria. Mineralogical Magazine, 90 (1). 181-191 doi:10.1180/mgm.2025.10116
Localities for Fanfaniite
Showing 6 localities.
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and 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).
All localities listed without proper references should be considered as questionable.
France | |
| ROATTINO. T et al. (2019) |
| Roattino et al. (2019) | |
Germany | |
| Grey et al. (2026) |
| Essefi (2020) |
Spain | |
| Calvo Rebollar et al. (2022) |
USA (TL) | |
| Hålenius et al. (2018) +1 other reference |
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The
Pegmatite field, Argelès-sur-Mer, Céret, Pyrénées-Orientales, Occitanie, France