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Fairfieldite
A valid IMA mineral species - grandfathered
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About Fairfieldite
Formula:
Ca2Mn2+(PO4)2 · 2H2O
Colour:
White, greenish white, light amber, salmon-yellow; colourless in transmitted light.
Lustre:
Sub-Vitreous, Waxy, Pearly
Hardness:
3½
Specific Gravity:
3.08 - 3.11
Crystal System:
Triclinic
Member of:
Name:
Named in 1878 by George J. Brush and Edward S. Dana after Fairfield County, Connecticut, USA, the type locality.
Unique Identifiers
Mindat ID:
1443
Long-form identifier:
mindat:1:1:1443:0
IMA Classification of Fairfieldite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca2Mn2+(PO4)2·2H2O
First published:
1879
Classification of Fairfieldite
8.CG.05
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
G : With large and medium-sized cations, RO4:H2O = 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
G : With large and medium-sized cations, RO4:H2O = 1:1
40.2.2.1
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
2 : AB2(XO4)2·xH2O
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
2 : AB2(XO4)2·xH2O
19.12.38
19 : Phosphates
12 : Phosphates of Mn
19 : Phosphates
12 : Phosphates of Mn
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ffd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Ffd | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Fairfieldite
Sub-Vitreous, Waxy, Pearly
Transparency:
Transparent, Translucent
Comment:
Lustre on the perfect {001} cleavage is brilliant
Colour:
White, greenish white, light amber, salmon-yellow; colourless in transmitted light.
Comment:
May be slightly stained yellow
Streak:
White
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
On {001} perfect; on {010}, good; on {110}, distinct.
On {001} perfect; on {010}, good; on {110}, distinct.
Fracture:
Irregular/Uneven
Density:
3.08 - 3.11 g/cm3 (Measured) 3.095 g/cm3 (Calculated)
Comment:
Measured value on Branchville material.
Optical Data of Fairfieldite
Type:
Biaxial (+)
RI values:
nα = 1.633 - 1.640 nβ = 1.641 - 1.650 nγ = 1.652 - 1.660
2V:
Measured: 86° , Calculated: 86° to 88°
Birefringence:
0.019
Max. Birefringence:
δ = 0.019 - 0.020
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:
High (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.
Dispersion:
r>v relatively weak
Optical Extinction:
X (120°,60°); Y (–102°,36°); Z (18°,69°) using (φ,ρ).
Pleochroism:
Non-pleochroic
Chemistry of Fairfieldite
Mindat Formula:
Ca2Mn2+(PO4)2 · 2H2O
Element Weights:
Crystallography of Fairfieldite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 5.78 Å, b = 6.57 Å, c = 5.48 Å
α = 102.08°, β = 108.71°, γ = 90.09°
α = 102.08°, β = 108.71°, γ = 90.09°
Ratio:
a:b:c = 0.88 : 1 : 0.834
Unit Cell V:
192.21 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Crystals prismatic to equant; frequently composite. Commonly in foliated to lamellar crystalline aggregates, superficially resembling gypsum at times. Curved, foliated or fibrous at times; radiating masses.
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0006119 | Fairfieldite | Herwig S, Hawthorne F C (2006) The topology of hydrogen bonding in brandtite, collinsite and fairfieldite The Canadian Mineralogist 44 1181-1196 |  | 2006 | Foote mine, North Carolina, USA | 0 | 293 |
| 0009374 | Fairfieldite | Fanfani L, Nunzi A, Zanazzi P F (1970) The crystal structure of fairfieldite Acta Crystallographica B26 640-645 |  | 1970 | Foote Mine, North Carolina, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.40 Å | (90) |
| 3.23 Å | (100) |
| 3.20 Å | (70) |
| 3.03 Å | (80) |
| 2.86 Å | (70) |
| 2.66 Å | (70) |
| 2.63 Å | (70) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47e : [Vanadates, chromates, manganates] |
Geological Setting:
Late stage phosphate mineralization in granite pegmatite.
Type Occurrence of Fairfieldite
General Appearance of Type Material:
Massive crystalline aggregates; rarely in distinct crystals. Foliated to lamellar, sometimes resembling selenite. Also occasionally in radiating masses consisting of curved foliated or fibrous aggregates, resembling stilbite.
Place of Conservation of Type Material:
Yale University, New Haven, Connecticut, USA, 3.3118, 3.3123.
Geological Setting of Type Material:
Late stage phosphate mineralization in a granite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Fairfieldite
Other Language Names for Fairfieldite
Relationship of Fairfieldite to other Species
Member of:
Other Members of Collinsite Group:
| Anorthoroselite | Ca2Co(AsO4)2 · 2H2O | Tric. |
| Cassidyite | Ca2Ni(PO4)2 · 2H2O | Tric. |
| Collinsite | Ca2Mg(PO4)2 · 2H2O | Tric. 1 : P1 |
| Gaitite | Ca2Zn(AsO4)2 · 2H2O | Tric. 1 : P1 |
| Hillite | Ca2Zn(PO4)2 · 2H2O | Tric. 1 : P1 |
| Messelite | Ca2Fe2+(PO4)2 · 2H2O | Tric. 1 : P1 |
| Nickeltalmessite | Ca2Ni(AsO4)2 · 2H2O | Tric. 1 : P1 |
| Parabrandtite | Ca2Mn2+(AsO4)2 · 2H2O | Tric. 1 : P1 |
| Talmessite | Ca2Mg(AsO4)2 · 2H2O | Tric. 1 : P1 |
| 'Unnamed (Fe2+-analogue of Parabrandtite)' | Ca2Fe2+(AsO4)2 · 2H2O |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 24 photos of Fairfieldite associated with Fluorapatite | Ca5(PO4)3F |
| 18 photos of Fairfieldite associated with Eosphorite | Mn2+Al(PO4)(OH)2 · H2O |
| 16 photos of Fairfieldite associated with Quartz | SiO2 |
| 15 photos of Fairfieldite associated with Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O |
| 14 photos of Fairfieldite associated with Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O |
| 13 photos of Fairfieldite associated with Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O |
| 11 photos of Fairfieldite associated with Albite | Na(AlSi3O8) |
| 11 photos of Fairfieldite associated with Hureaulite | Mn2+5(PO3OH)2(PO4)2 · 4H2O |
| 10 photos of Fairfieldite associated with Muscovite | KAl2(AlSi3O10)(OH)2 |
| 8 photos of Fairfieldite associated with Lithiophilite | LiMn2+PO4 |
Related Minerals - Strunz-mindat Grouping
| 8.CG. | Fluckite | CaMn2+(AsO3OH)2 · 2H2O |
| 8.CG. | Dondoellite | Ca2Fe(PO4)2 · 2H2O |
| 8.CG. | 'Ca-Huréaulite' | CaMn5(PO4)4 · 4H2O |
| 8.CG. | Alumolukrahnite | Ca[CuAl](AsO4)2(H2O,OH)2 |
| 8.CG.05 | Parabrandtite | Ca2Mn2+(AsO4)2 · 2H2O |
| 8.CG.05 | Talmessite | Ca2Mg(AsO4)2 · 2H2O |
| 8.CG.05 | Collinsite | Ca2Mg(PO4)2 · 2H2O |
| 8.CG.05 | Messelite | Ca2Fe2+(PO4)2 · 2H2O |
| 8.CG.05 | Gaitite | Ca2Zn(AsO4)2 · 2H2O |
| 8.CG.05 | Anorthoroselite | Ca2Co(AsO4)2 · 2H2O |
| 8.CG.05 | Cassidyite | Ca2Ni(PO4)2 · 2H2O |
| 8.CG.05 | Hillite | Ca2Zn(PO4)2 · 2H2O |
| 8.CG.05 | 'Unnamed (Fe2+-analogue of Parabrandtite)' | Ca2Fe2+(AsO4)2 · 2H2O |
| 8.CG.10 | Zincroselite | Ca2Zn(AsO4)2 · 2H2O |
| 8.CG.10 | Roselite | Ca2Co(AsO4)2 · 2H2O |
| 8.CG.10 | Rruffite | Ca2Cu(AsO4)2 · 2H2O |
| 8.CG.10 | Wendwilsonite | Ca2Mg(AsO4)2 · 2H2O |
| 8.CG.10 | Brandtite | Ca2Mn2+(AsO4)2 · 2H2O |
| 8.CG.10 | 'Unnamed (Fe2+-analogue of Brandtite)' | Ca2Fe2+(AsO4)2 · 2H2O |
| 8.CG.15 | Mawbyite | PbFe3+2(AsO4)2(OH)2 |
| 8.CG.15 | Thometzekite | PbCu2+2(AsO4)2 · 2H2O |
| 8.CG.15 | Yancowinnaite | PbCuAl(AsO4)2OH · H2O |
| 8.CG.15 | Schneebergite | BiCo2(AsO4)2(OH) · H2O |
| 8.CG.15 | Cabalzarite | CaMg2(AsO4)2 · 2H2O |
| 8.CG.15 | Nickelschneebergite | BiNi2(AsO4)2(OH) · H2O |
| 8.CG.15 | Lotharmeyerite | CaZn2(AsO4)2 · 2H2O |
| 8.CG.15 | Nickeltsumcorite | Pb(Ni,Fe3+)2(AsO4)2(H2O,OH)2 |
| 8.CG.15 | Magnesiofluckite | CaMg(AsO3OH)2(H2O)2 |
| 8.CG.15 | Krettnichite | PbMn3+2(VO4)2(OH)2 |
| 8.CG.15 | Cobalttsumcorite | PbCo2(AsO4)2 · 2H2O |
| 8.CG.15 | Manganlotharmeyerite | CaMn3+2(AsO4)2(OH)2 |
| 8.CG.15 | Tsumcorite | PbZn2(AsO4)2 · 2H2O |
| 8.CG.15 | Ferrilotharmeyerite | CaZnFe3+(AsO4)2(OH) · H2O |
| 8.CG.15 | Cobaltlotharmeyerite | CaCo2(AsO4)2 · 2H2O |
| 8.CG.15 | Mounanaite | PbFe3+2(VO4)2(OH)2 |
| 8.CG.15 | Nickellotharmeyerite | CaNi2(AsO4)2 · 2H2O |
| 8.CG.20 | Lukrahnite | CaCuFe3+(AsO4)2(OH,H2O)2 |
| 8.CG.20 | Helmutwinklerite | PbZn2(AsO4)2 · 2H2O |
| 8.CG.20 | Phosphogartrellite | PbCuFe3+(PO4)2(OH,H2O)2 |
| 8.CG.20 | Gartrellite | PbCuFe3+(AsO4)2(OH) · H2O |
| 8.CG.20 | Zincgartrellite | PbZn2(AsO4)2(H2O,OH)2 |
| 8.CG.20 | Rappoldite | PbCo2(AsO4)2 · 2H2O |
| 8.CG.25 | Pottsite | (Pb3xBi4-2x)(VO4)4 · H2O (0.8 < x < 1.0) |
| 8.CG.25 | Armellinoite-(Ce) | Ca4Ce4+(AsO4)4 · H2O |
| 8.CG.35 | Nickeltalmessite | Ca2Ni(AsO4)2 · 2H2O |
| 8.CG.55 | Irhtemite | Ca4Mg(AsO4)2(HAsO4)2 · 4H2O |
Fluorescence of Fairfieldite
Not fluorescent in UV.
Other Information
Notes:
Soluble in acids.
Found as an alteration product of Dickinsonite and as pseudomorphs after Rhodochrosite.
Found as an alteration product of Dickinsonite and as pseudomorphs after Rhodochrosite.
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 Fairfieldite
mindat.org URL:
https://www.mindat.org/min-1443.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Fairfieldite
Reference List:
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.74
Landes, Kenneth K. (1925) The paragenesis of the granite pegmatites of central Maine. American Mineralogist, 10 (11) 355-411 p.386
Berman, Harry, Gonyer, F. A. (1930) Pegmatite minerals of Poland, Maine. American Mineralogist, 15 (8) 375-387
Wolfe, C. W. (1940) Classification of minerals of the type A3(XO4)2·nH2O. American Mineralogist, 25 (11) 738-753 p.748
Frondel, Clifford (1955) Neomesselite and beta-roselite: Two new members of the fairfieldite group. American Mineralogist, 40 (9-10) 828-833
Fanfani, L., Nunzi, A., Zanazzi, P. F. (1970) The crystal structure of fairfieldite. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 26 (5) 640-645 doi:10.1107/s0567740870002893
Fleck, Michel, Kolitsch, U., Hertweck, B. (2002) Natural and synthetic compounds with kröhnkite-type chains: review and classification. Zeitschrift für Kristallographie, 217 (9). 435-443 doi:10.1524/zkri.217.9.435.22883
Herwig, S.; Hawthorne, F. C. (2006) The topology of hydrogen bonding in brandtite, collinsite and fairfieldite. The Canadian Mineralogist, 44 (5). 1181-1196 doi:10.2113/gscanmin.44.5.1181
Frost, Ray L. (2009) Raman and infrared spectroscopy of arsenates of the roselite and fairfieldite mineral subgroups. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 71 (5) 1788-1794 doi:10.1016/j.saa.2008.06.039
Frost, Ray L., Xi, Yunfei, Scholz, Ricardo, Belotti, Fernanda Maria, Lopez, Andres (2013) Infrared and Raman spectroscopic characterization of the phosphate mineral fairfieldite – Ca2(Mn2+,Fe2+)2(PO4)2·2(H2O) Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 106. 216-223 doi:10.1016/j.saa.2013.01.008
Localities for Fairfieldite
Showing 90 localities.
symbol to view information about a locality.
The 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.
Argentina | |
| Mr. Nelson Valenzuela. |
| GALLISKI (1983) +1 other reference |
| Galliski et al. (2002) | |
Australia | |
| Pring et al. (2000) |
Austria | |
| Niedermayr et al. (1988) +1 other reference |
Brazil | |
| Moore (2005) +1 other reference |
| Sergio Varvello collection |
| Baijot et al. (2012) |
| Martins da Pedra collection |
Canada | |
| 153-155. +2 other references |
China | |
| Wang et al. (2021) |
| Chen et al. (2026) |
Czech Republic | |
| Masau +2 other references |
| Staněk (1991) +4 other references |
| Staněk (1997) | |
Finland | |
| Lahti (1981) |
| Sandström et al. (2009) | |
| Ilkka Mikkola collection |
Germany | |
| Palache et al. (1951) +2 other references |
| Weiß (1990) +1 other reference |
| web.archive.org (2001) | |
| Dill et al. (2008) | |
Iran | |
| |
Italy | |
| VIGNOLA et al. (2007) |
| Vignola et al. (2011) +1 other reference | |
| Vignola et al. (2018) |
Morocco | |
| Favreau (2012) |
Namibia | |
| in the collection from F.J.Emmerich |
Poland | |
| Pieczka A. et al. (2004) |
| Twardak et al. (2018) |
| Włodek et al. (2011) +1 other reference |
| Pieczka et al. (2015) |
| Pieczka et al. (2015) +2 other references |
Portugal | |
| Schnorrer-Köhler et al. (1991) |
| Alves (n.d.) | |
| Self-find by Nuno Afonso +1 other reference |
| Martins et al. (2011) |
| Rewitzer et al. (1984) +1 other reference |
| Pedro Alves collection (p-XRD and SEM EDS analysed samples) | |
| Mineralien Atlas | |
| Pedro Alves analytical data and ... |
Russia | |
| Pekov (1998) |
Spain | |
| Dill et al. (2023) |
| Roda et al. (2001) |
| Christian Rewitzer collection +1 other reference |
| De las Heras et al. (1989) |
Sweden | |
| Sandström (2008) |
Switzerland | |
| Stalder et al. (1998) |
USA | |
| London et al. (1982) |
| London et al. (1982) |
| Fisher (2002) |
| with a description of several new species occurring there. American Journal of Science and Arts et al. (123-123) +6 other references |
| Schooner (circa 1980s) |
| Schooner (circa 1985) +1 other reference |
| |
| King et al. (1994) |
| Rocks and Minerals (1999) +2 other references |
| King et al. (1994) +1 other reference |
| Maine Pegmatite Workshop 2004 |
| King et al. (1994) | |
| Moore (1973) +1 other reference | |
| Mineral News (1995) +2 other references |
| King et al. (1994) |
| King et al. (1994) +1 other reference |
| King et al. (1994) +1 other reference | |
| King et al. (1994) | |
| King et al. (1994) +1 other reference | |
| |
| King et al. (1994) |
| Dionne et al. (2014) |
| Thompson et al. (1998) |
| King et al. (1994) | |
| Tim Blake | |
| W. B. Thompson et al. (2005) |
| Smith (2005) |
| Kevin Czaja Collection |
| Etienne Médard collection |
| Rocks & Minerals: 16: 208-211. +6 other references |
| Geological Society of America Abstracts ... +2 other references | |
| Rocks & Minerals 80:4 pp234-241 +3 other references |
| Brannock (1967) +4 other references |
| The Geological Society Of America +1 other reference | |
| Smithsonian Institution Mineral ... | |
| Smith et al. (2000) |
| Rocks & Minerals: 60: 117. +1 other reference |
| Rocks & Min.:10:147 & 60:112 |
| Smith et al. (2000) | |
| Liferovich et al. (1998) |
Quick NavTopAbout FairfielditeUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Foote Lithium Co. Mine, Kings Mountain, Cleveland County, North Carolina, USA