Reddingite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Reddingite
Formula:
(Mn2+,Fe2+)3(PO4)2 · 3H2O
Colour:
Colourless, pale pink or yellow, reddish brown to dark brown (altered); colourless, faintly tinted pink in transmitted light
Lustre:
Vitreous, Resinous
Hardness:
3½
Specific Gravity:
3 - 3.2
Crystal System:
Orthorhombic
Member of:
Name:
For the type locality at Branchville, in the town of Redding, Fairfield Co., Connecticut, USA.
Phosphoferrite Group, Phosphoferrite-Reddingite Series.
Note: Some "reddingites" may in fact be correianevesite.
Note: Some "reddingites" may in fact be correianevesite.
Unique Identifiers
Mindat ID:
3378
Long-form identifier:
mindat:1:1:3378:3
Similar Names
| Reddingite (of Steinmetz) | A synonym of Phosphoferrite |
| Rodingite | A rock classification type |
IMA Classification of Reddingite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+3(PO4)2·3H2O
First published:
1878
Classification of Reddingite
8.CC.05
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
C : With only medium-sized cations, RO4:H2O = 1:1.5
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
C : With only medium-sized cations, RO4:H2O = 1:1.5
40.3.2.3
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
3 : A3(XO4)2·xH2O
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
3 : A3(XO4)2·xH2O
19.12.20
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 |
|---|---|---|
| Rdd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Rdd | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Reddingite
Vitreous, Resinous
Transparency:
Transparent, Translucent
Comment:
Lustre extends to sub-resinous from vitreous.
Colour:
Colourless, pale pink or yellow, reddish brown to dark brown (altered); colourless, faintly tinted pink in transmitted light
Streak:
White
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
On {010}, poor.
On {010}, poor.
Fracture:
Irregular/Uneven
Density:
3 - 3.2 g/cm3 (Measured) 3.24 g/cm3 (Calculated)
Comment:
Calculated value is for Mn:Fe = 3:1.
Optical Data of Reddingite
Type:
Biaxial (+)
RI values:
nα = 1.643 - 1.658 nβ = 1.648 - 1.664 nγ = 1.674 - 1.685
2V:
Measured: 41° to 65°, Calculated: 48° to 58°
Max. Birefringence:
δ = 0.027 - 0.031
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:
Very 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:
strong
Optical Extinction:
Parallel. X = a; Y = b; Z = c.
Pleochroism:
Visible
Comments:
Buckfield, Maine material:
X = colourless; Y = pinkish brown; Z = pale yellow.
X = colourless; Y = pinkish brown; Z = pale yellow.
Chemistry of Reddingite
Mindat Formula:
(Mn2+,Fe2+)3(PO4)2 · 3H2O
Element Weights:
Common Impurities:
Fe
Crystallography of Reddingite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pmna
Cell Parameters:
a = 9.49 Å, b = 10.08 Å, c = 8.7 Å
Ratio:
a:b:c = 0.941 : 1 : 0.863
Unit Cell V:
832.24 ų (Calculated from Unit Cell)
Morphology:
Crystals pseudo-octahedral with large {111}, or tabular {010}. The crystals are frequently in parallel grouping. Massive, granular; coarsely fibrous. Forms include {111}, {212}, {221}, {010}, {223}, {122}.
Crystallographic forms of Reddingite
Crystal Atlas:
Image Loading
Click on an icon to view
Reddingite no.1 - {111} - Goldschmidt (1913-1926)
Reddingite no.2 - {111} - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by
www.smorf.nl.
Toggle
Edge Lines | Miller Indices | Axes
Transparency
Opaque | Translucent | Transparent
View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation
Edge Lines | Miller Indices | Axes
Transparency
Opaque | Translucent | Transparent
View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.20 Å | (100) |
| 2.737 Å | (80) |
| 4.28 Å | (70) |
| 2.657 Å | (70) |
| 2.422 Å | (70) |
| 2.234 Å | (70) |
| 1.625 Å | (70) |
Comments:
Hagendorf, Germany. The pattern is similar to that of phosphoferrite.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Type Occurrence of Reddingite
General Appearance of Type Material:
Minute orthorhombic octahedral crystals. Also massive and granular.
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
Granite pegmatite.
Associated Minerals at Type Locality:
Other Language Names for Reddingite
Relationship of Reddingite to other Species
Member of:
Other Members of Reddingite Group:
| Correianevesite | Fe2+Mn2+2(PO4)2 · 3H2O | Orth. mmm(2/m2/m2/m) |
| Garyansellite | Mg2Fe3+(PO4)2(OH) · 2H2O | Orth. mmm(2/m2/m2/m) |
| Kryzhanovskite | (Fe3+,Mn2+)3(PO4)2(OH,H2O)3 | Orth. mmm(2/m2/m2/m) |
| Landesite | Mn2+3-xFe3+x(PO4)2(OH)x · (3-x)H2O | Orth. mmm(2/m2/m2/m) |
| Phosphoferrite | (Fe2+,Mn2+)3(PO4)2 · 3H2O | Orth. mmm(2/m2/m2/m) : Pmna |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 27 photos of Reddingite associated with Hureaulite | Mn2+5(PO3OH)2(PO4)2 · 4H2O |
| 14 photos of Reddingite associated with Rockbridgeite | (Fe2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5 |
| 12 photos of Reddingite associated with Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O |
| 9 photos of Reddingite associated with Dickinsonite-(KMnNa) | (KNa)(Mn2+◻)Ca(Na2Na)Mn2+13Al(PO4)11(PO4)(OH)2 |
| 7 photos of Reddingite associated with Triphylite | LiFe2+PO4 |
| 5 photos of Reddingite associated with Quartz | SiO2 |
| 4 photos of Reddingite associated with Landesite | Mn2+3-xFe3+x(PO4)2(OH)x · (3-x)H2O |
| 3 photos of Reddingite associated with Correianevesite | Fe2+Mn2+2(PO4)2 · 3H2O |
| 2 photos of Reddingite associated with Rhodochrosite | MnCO3 |
| 2 photos of Reddingite associated with Lithiophilite | LiMn2+PO4 |
Related Minerals - Strunz-mindat Grouping
| 8.CC. | Correianevesite | Fe2+Mn2+2(PO4)2 · 3H2O |
| 8.CC.05 | Landesite | Mn2+3-xFe3+x(PO4)2(OH)x · (3-x)H2O |
| 8.CC.05 | Garyansellite | Mg2Fe3+(PO4)2(OH) · 2H2O |
| 8.CC.05 | Phosphoferrite | (Fe2+,Mn2+)3(PO4)2 · 3H2O |
| 8.CC.05 | Kryzhanovskite | (Fe3+,Mn2+)3(PO4)2(OH,H2O)3 |
| 8.CC.10 | Kaatialaite | Fe3+[AsO2(OH)2]3 · 5H2O |
| 8.CC.15 | Leogangite | Cu10(AsO4)4(SO4)(OH)6 · 8H2O |
Other Information
Thermal Behaviour:
Heating in the closed tube, it whitens at first, then turns yellow and finally brown, but does not become magnetic.
Before the blowpipe, colors the flame pale green and fuses easily (scale = 2) to a blackish-brown non-magnetic globule.
Before the blowpipe, colors the flame pale green and fuses easily (scale = 2) to a blackish-brown non-magnetic globule.
Notes:
Soluble in hydrochloric and nitric acids.
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 Reddingite
mindat.org URL:
https://www.mindat.org/min-3378.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 Reddingite
Reference List:
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.126
Landes, Kenneth K. (1925) The paragenesis of the granite pegmatites of central Maine. American Mineralogist, 10 (11) 355-411 p.387
Steinmetz, H. (1926) Phosphophyllit und Reddingit von Hagendorf. Zeitschrift für Kristallographie, Mineralogie und Petrographie, 64 (1-6). 405-412 doi:10.1524/zkri.1926.64.1.405
Berman, Harry, Gonyer, F. A. (1930) Pegmatite minerals of Poland, Maine. American Mineralogist, 15 (8) 375-387 p.379
Wolfe, C. W. (1940) Classification of minerals of the type A3(XO4)2·nH2O. American Mineralogist, 25 (11) 738-753
Moore, Paul Brian., Araki, Takaharu. (1976) Mixed-valence solid-solution series. Crystal structures of phosphoferrite, Fe32+(H2O)3[PO4]2, and kryzhanovskite, Fe33+(OH)3[PO4]2. Inorganic Chemistry, 15 (2) 316-321 doi:10.1021/ic50156a015
Moore, P. B., Araki, T., Kampf, A. R. (1980) Nomenclature of the phosphoferrite structure type: refinements of landesite and kryzhanovskite. Mineralogical Magazine, 43 (330) 789-795 doi:10.1180/minmag.1980.043.330.14
Frost, Ray L., Xi, Yunfei, Scholz, Ricardo, Belotti, Fernanda M., Lagoeiro, Leonardo E. (2012) Chemistry, Raman and infrared spectroscopic characterization of the phosphate mineral reddingite: (MnFe)3(PO4)2(H2O,OH)3, a mineral found in lithium-bearing pegmatite. Physics and Chemistry of Minerals, 39 (10) 803-810 doi:10.1007/s00269-012-0535-7
Localities for Reddingite
Showing 37 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 | |
| OYARZABAL et al. (H2O) |
| Roda-Robles et al. (2012) |
Brazil | |
| Peter Kohorst collection |
| Fabre (n.d.) +2 other references |
| Mike Scott S104310 from Cureton #HC ... |
| Atencio et al. (2004) |
| Sergio Varvello collection |
China | |
| Qi Zhou et al. (2013) |
Finland | |
| Lahti (1981) |
| Sandström et al. (2009) | |
France | |
| Patrice Queneau Collection. Visual ... |
Germany | |
| Weiß (1990) |
| web.archive.org (2001) | |
| Weiß (1990) |
| DILL et al. (2009) | |
Japan | |
| Matsubara et al. (1980) |
Portugal | |
| Schnorrer-Köhler et al. (1991) |
| Alves (n.d.) | |
| Leal Gomes et al. (2009) |
| 4 +4 other references |
| Angel Roldán Herrero collection |
| Mineralien Atlas | |
Spain | |
| Roda et al. (2001) |
USA (TL) | |
| Brush and Dana (1878) +3 other references |
| Schooner (circa 1985) |
| Palache et al. (1951) +1 other reference |
| Landes (1925) |
| Falster et al. (2019) |
| King et al. (1994) +1 other reference |
| King et al. (1994) |
| Czaja (2025) |
| Morrill +1 other reference |
| Morrill |
| Rocks & Minerals 80:4 pp234-241 +1 other reference |
| Jason Smith collection |
| Januzzi et al. (1976) |
| Smith et al. (2000) |
Quick NavTopAbout ReddingiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystallographic forms X-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany