Dufrénite
A valid IMA mineral species - grandfathered
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About Dufrénite
Ours-Pierre-Armand Petit-Dufrénoy
Formula:
Ca0.5Fe2+Fe3+5(PO4)4(OH)6 · 2H2O
Colour:
Dark green, olive-green, olive-brown, black; olive-brown to reddish brown with oxidation; bluish green to reddish brown or yellow in transmitted light.
Lustre:
Sub-Vitreous, Resinous, Silky
Hardness:
3½ - 4½
Specific Gravity:
3.1 - 3.34
Crystal System:
Monoclinic
Member of:
Name:
Named in 1833 by Alexandre Brongniart in honor of Ours Pierre Armand Petit Dufrenoy [September 5, 1792 - March 20, 1857), Professor of Mineralogy in the École des Mines, Paris, France. (Because of many look-alike species in the environments where dufrénite occurred, species such as rockbridgeite, etc. were called by that name.)
The mineral dufrénoysite is also named in his honor.
The mineral dufrénoysite is also named in his honor.
Co-Type Localities:
Isostructural with:
A secondary mineral occurring with limonite in gossan of veins and in iron ore deposits.
See also natrodufrénite which is visually indistinguishable from dufrénite and appears to be much more common than presently thought (Henry Barwood, unpubl. results).
A (formally) vacancy- and Mn2+-dominant member was reported by Sejkora et al. (2006).
Note: dufrénite is the correct spelling, not dufrenite (Burke, 2008).
There are some dufrenite-like species, e.g., 'UM1949-01-PO:Fe'.
See also natrodufrénite which is visually indistinguishable from dufrénite and appears to be much more common than presently thought (Henry Barwood, unpubl. results).
A (formally) vacancy- and Mn2+-dominant member was reported by Sejkora et al. (2006).
Note: dufrénite is the correct spelling, not dufrenite (Burke, 2008).
There are some dufrenite-like species, e.g., 'UM1949-01-PO:Fe'.
Unique Identifiers
Mindat ID:
1323
Long-form identifier:
mindat:1:1:1323:5
GUID
(UUID V4):
(UUID V4):
fbc21625-7573-48ad-82f9-4ea17e64c288
IMA Classification of Dufrénite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca0.5Fe2+Fe3+5(PO4)4(OH)6 · 2H2O
Classification of Dufrénite
8.DK.15
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
K : With large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
K : With large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1
42.9.1.2
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
9 : (AB)7(XO4)4Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
9 : (AB)7(XO4)4Zq·xH2O
19.13.4
19 : Phosphates
13 : Phosphates of Fe alone
19 : Phosphates
13 : Phosphates of Fe alone
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 |
|---|---|---|
| Dfr | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Dfr | 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 Dufrénite
Sub-Vitreous, Resinous, Silky
Transparency:
Translucent, Opaque
Comment:
Silky in cross-section of botryoids
Colour:
Dark green, olive-green, olive-brown, black; olive-brown to reddish brown with oxidation; bluish green to reddish brown or yellow in transmitted light.
Streak:
Green
Hardness:
3½ - 4½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
One perfect, a second cleavage good and both parallel to the fibre direction, with traces of a poor third cleavage at right angles to the other two.
One perfect, a second cleavage good and both parallel to the fibre direction, with traces of a poor third cleavage at right angles to the other two.
Fracture:
Fibrous
Density:
3.1 - 3.34 g/cm3 (Measured) 3.41 g/cm3 (Calculated)
Optical Data of Dufrénite
Type:
Biaxial (+/-)
RI values:
nα = 1.820 - 1.842 nβ = 1.830 - 1.850 nγ = 1.875 - 1.925
2V:
Calculated: 38° to 52°
Birefringence:
0.055
Max Birefringence:
δ = 0.055 - 0.083
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:
Very High
Dispersion:
rv relatively strong
Pleochroism:
Visible
Comments:
X = Deep blue, light brown, light yellow-brown or deep bluish green
Y = Buff, brown, light brown, light yellow-brown
Z = Deep red-brown, dark brown, red-brown, deep olive-brown
(from localities: Rock Run, AL; Siegen, Westphalia; Wheal Phoenix; and Hirs
Y = Buff, brown, light brown, light yellow-brown
Z = Deep red-brown, dark brown, red-brown, deep olive-brown
(from localities: Rock Run, AL; Siegen, Westphalia; Wheal Phoenix; and Hirs
Chemistry of Dufrénite
Mindat Formula:
Ca0.5Fe2+Fe3+5(PO4)4(OH)6 · 2H2O
Crystallography of Dufrénite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 25.84(2) Å, b = 5.126(3) Å, c = 13.78(1) Å
β = 111.20(6)°
β = 111.20(6)°
Ratio:
a:b:c = 5.041 : 1 : 2.688
Unit Cell V:
1,701.72 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Crystals rare, indistinct, in subparallel or sheaf-like aggregates. Botryoidal masses or crusts with a radial-fibrous structure, common. The crusts are formed of drusy crystals with rounded or exfoliated terminations at times.
Comment:
SG C2/c
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.00 Å | (9) |
| 5.002 Å | (9) |
| 4.410 Å | (5) |
| 3.393 Å | (7) |
| 3.151 Å | (10) |
| 2.860 Å | (6) |
| 2.101 Å | (5) |
Comments:
Close to natrodufrénite.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-𝑇 subsurface aqueous alteration (see also #23) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] |
Geological Setting:
Gossan of veins and in iron ore deposits; in iron-rich gossans; rarely in late-stage phosphate mineralization in granite pegmatites.
Type Occurrence of Dufrénite
Co-Type Localities:
Place of Conservation of Type Material:
Muséum Nationale d’Histoire Naturelle, Paris, France, number42.47.
Geological Setting of Type Material:
Iron ore deposit
Associated Minerals at Type Locality:
Synonyms of Dufrénite
Other Language Names for Dufrénite
German:Dufrénit
Grüneisenerde
Grüneisenerz
Grüneisenstein, strahlicher, ochricher
Kraurit
Strahlstein (of Jordan)
Olivenerz (in part)
Grüneisenerde
Grüneisenerz
Grüneisenstein, strahlicher, ochricher
Kraurit
Strahlstein (of Jordan)
Olivenerz (in part)
Russian:Дюфренит
Simplified Chinese:绿磷铁矿
Spanish:Dufrénita
Traditional Chinese:綠燐鐵礦
Relationship of Dufrénite to other Species
Member of:
Other Members of this group:
| Bimbowrieite | NaMgFe3+5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
| Burangaite | NaFe2+Al5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
| Gayite | NaMn2+Fe3+5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
| Matioliite | NaMgAl5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
| Natrodufrénite | NaFe2+Fe3+5(PO4)4(OH)6 · 2H2O | Mon. 2/m : B2/b |
Common Associates
Associated Minerals Based on Photo Data:
| 79 photos of Dufrénite associated with Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O |
| 77 photos of Dufrénite associated with Kidwellite | NaFe3+9+x(PO4)6(OH)11 · 3H2O, x = 0.33 |
| 49 photos of Dufrénite associated with Strengite | FePO4 · 2H2O |
| 47 photos of Dufrénite associated with Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O |
| 43 photos of Dufrénite associated with Cyrilovite | NaFe3+3(PO4)2(OH)4 · 2H2O |
| 40 photos of Dufrénite associated with Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
| 35 photos of Dufrénite associated with Chalcosiderite | CuFe3+6(PO4)4(OH)8 · 4H2O |
| 34 photos of Dufrénite associated with Goethite | α-Fe3+O(OH) |
| 33 photos of Dufrénite associated with Bariopharmacosiderite | Ba0.5Fe3+4(AsO4)3(OH)4 · 5H2O |
| 23 photos of Dufrénite associated with Rockbridgeite | Fe2+Fe3+4(PO4)3(OH)5 |
Related Minerals - Strunz-mindat Grouping
| 8.DK. | Richelsdorfite | Ca2Cu5Sb(AsO4)4(OH)6Cl · 6H2O |
| 8.DK. | Bimbowrieite | NaMgFe3+5(PO4)4(OH)6 · 2H2O |
| 8.DK. | Puttapaite | Pb2Mn2+2ZnCr3+4O2(AsO4)4(OH)6 · 12H2O |
| 8.DK.10 | Bariopharmacosiderite | Ba0.5Fe3+4(AsO4)3(OH)4 · 5H2O |
| 8.DK.10 | Pharmacosiderite | KFe3+4(AsO4)3(OH)4 · 6-7H2O |
| 8.DK.10 | Natropharmacosiderite | NaFe3+4(AsO4)3(OH)4 · 4H2O |
| 8.DK.10 | Hydroniumpharmacosiderite | (H3O)Fe4(AsO4)3(OH)4 · 4H2O |
| 8.DK.10 | Strontiopharmacosiderite | Sr0.5Fe4[(AsO4)3(OH)4] · 4H2O |
| 8.DK.10 | Thalliumpharmacosiderite | TlFe4[(AsO4)3(OH)4] · 4H2O |
| 8.DK.10 | Plumbopharmacosiderite | Pb0.5Fe3+4(AsO4)3(OH)4 · 5H2O |
| 8.DK.12 | Pharmacoalumite | KAl4(AsO4)3(OH)4 · 6.5H2O |
| 8.DK.12 | Natropharmacoalumite | NaAl4(AsO4)3(OH)4 · 4H2O |
| 8.DK.12 | Bariopharmacoalumite | Ba0.5Al4(AsO4)3(OH)4 · 4H2O |
| 8.DK.12 | Hydroniumpharmacoalumite | (H3O)Al4(AsO4)3(OH)4 · 4.5H2O |
| 8.DK.15 | Burangaite | NaFe2+Al5(PO4)4(OH)6 · 2H2O |
| 8.DK.15 | Natrodufrénite | NaFe2+Fe3+5(PO4)4(OH)6 · 2H2O |
| 8.DK.15 | Matioliite | NaMgAl5(PO4)4(OH)6 · 2H2O |
| 8.DK.15 | Gayite | NaMn2+Fe3+5(PO4)4(OH)6 · 2H2O |
| 8.DK.20 | Kidwellite | NaFe3+9+x(PO4)6(OH)11 · 3H2O, x = 0.33 |
| 8.DK.25 | Bleasdaleite | (Ca,Fe3+)2Cu5(Bi,Cu)(PO4)4(H2O,OH,Cl)13 |
| 8.DK.30 | Matulaite | (Fe3+,Al)Al7(PO4)4(PO3OH)2(OH)8(H2O)8 · 8H2O |
| 8.DK.35 | Krasnovite | Ba(Al,Mg)(PO4,CO3)(OH)2 · H2O |
Fluorescence of Dufrénite
Not Fluorescent in UV
Other Information
Notes:
Soluble in dilute 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 Dufrénite
mindat.org URL:
https://www.mindat.org/min-1323.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 Dufrénite
Reference List:
Van Der Westhuizen, W. A., de Bruiyn, H., Beukes, G. J., Strydom, D. (1990) Dufrenite in iron-formation on the Kangnas farm, Aggeneys district, Bushmanland, South Africa. Mineralogical Magazine, 54 (376) 419-424 doi:10.1180/minmag.1990.054.376.07
Burke, Ernst A. J. (2008) Tidying up mineral names: an IMA-CNMNC scheme for suffixes, hyphens and diacritical marks. The Mineralogical Record, 39 (2) 131-135
Localities for Dufrénite
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 | |
| Dina (1993) |
| Demartin et al. (1997) | |
| Gay et al. (1991) +1 other reference |
| OYARZABAL et al. (H2O) +2 other references |
| Roda-Robles et al. (2012) |
Australia | |
| Birch et al. (1997) |
| Birch et al. (1997) |
| Day (1998) | |
| Johnson (1956) |
| Stuart Mills |
| Derrick +1 other reference |
| Francis (2010) |
| Francis (2010) | |
| Francis (2010) | |
| |
| Sorrell (n.d.) +1 other reference |
| Australian Journal of Mineralogy. Vol ... |
| Harrowfield et al. (1981) |
| Frost et al. (2004) |
| Noble et al. (1983) |
| Birch et al. (1993) |
| Sue Koepke collection |
| Collection of NHM | |
| Simpson (1920) |
| Peter Downes |
| Jacobson et al. (2007) |
Brazil | |
| Sergio Varvello collection |
| Cassedanne (1983) |
| Cassedanne et al. (1999) |
| Sergio Varvello collection |
Canada | |
| Ontario Mineral deposit Inventory ... |
Czech Republic | |
| A. Tomwek |
| Povondra et al. (eds.) +1 other reference |
| Černý et al. (Weisser Stein) |
| Škoda |
| Prachař +6 other references |
| Weber |
| Janouš +4 other references |
| Houzar S.: Přehled minerálů z ... +1 other reference |
Europe | |
| Berbain et al. (2012) | |
France | |
| Chollet Pascal Collection |
| Pierre Le Roch & Jean-Marc Johannet ... |
| Walenta et al. (1980) +1 other reference | |
| Chauris (2014) |
| Pierre Le Roc'h & Jean-Marc Johannet ... |
| Patureau et al. (2011) |
| Johannet (2006) |
| Lièvre et al. (2002) |
| perso.wanadoo.fr (2004) |
| Brongniart A: Tab. Espèces Min. (1833) |
| F-X Chatenet +1 other reference |
| Guide geologique de la Haute Vienne | |
| perso.wanadoo.fr (2005) |
| Berbain et al. (2012) |
Germany | |
| Walenta (1992) |
| Palache et al. (1951) +1 other reference |
| www.mineralienatlas.de (n.d.) |
| Dana 7:II:772 |
| 42. (in German) +2 other references |
| Dill et al. (2009) |
| www.berthold-weber.de (2001) |
| Laubmann et al. (1920) |
| Meier (2005) |
| www.mineralienatlas.de (n.d.) |
| Dana 6: 797 +1 other reference |
| Blaß (2002) |
| Wittern (2001) |
| D. Pawlowski: "Mineralfundstellen im Sauerland" (Munich) +1 other reference |
| Weiss: "Mineralienfundstellen et al. (Munich) |
| Hucko (2010) |
| Weiß (1990) +1 other reference | |
| Hucko (2010) |
| Marcus Voigt Collection |
| Weiss: "Mineralienfundstellen et al. (Munich) |
| Schaarschmidt (2014) |
| T. Witzke & T. Giesler (1993) |
| U. Ludwig |
| Pestel et al. (2012) | |
| Wittern (2001) |
| Witzke et al. (2001) |
| Witzke et al. (2001) |
Greece | |
| Kolitsch et al. (2014) +1 other reference |
| |
| Rieck et al. (2020) |
Hungary | |
| Körmendy Regina (2011) |
Italy | |
| Stara P. (1996) |
| Fadda (1989) |
Japan | |
| Matsubara et al. (1980) |
Madagascar | |
| Behier (1960) |
Mexico | |
| Michael Shannon specimens |
Morocco | |
| GAUDEFROY (1955) |
| Fontan (1978) |
Namibia | |
| von Bezing (2007) |
| Der Aufschluss 36:117-119 | |
| P. Keller and O. von Knorring |
| |
Poland | |
| Włodek et al. (2015) |
| Pieczka et al. (2015) |
Portugal | |
| Rui Nunes' collection |
| Alves (2016) |
| Pedro Alves collection |
| 4 +4 other references |
| Martins et al. (2011) |
| Rewitzer et al. (1984) +1 other reference |
| Pedro Alves collection and/or ... |
| Pedro Alves collection | |
Romania | |
| Szakáll |
| Szakáll et al. (2010) | |
| Szakáll et al. (2010) |
Rwanda | |
| Royal Museum for Central Africa |
| Daltry et al. (1998) |
South Africa | |
| Cairncross et al. (1995) |
| Cairncross et al. (1995) |
Spain | |
| Sáinz de Baranda et al. (2004) |
| www.foro-minerales.com (2022) +1 other reference | |
| Calvo Rebollar (2015) |
| Camprubí et al. (Catalunya) |
| Tritlla (1987) |
Sweden | |
| |
| |
UK | |
| Palache et al. (1951) +1 other reference |
| Kinch et al. (1886) +3 other references | |
| P D Trebilcock. | |
| Mineralogical Magazine 1996 60 : ... +1 other reference |
| Hartley (1984) +1 other reference |
| Stanley et al. (1991) | |
| Kingsbury (1957) |
USA | |
| Rob Lavinsky |
| Min.Rec.:20 (5) +1 other reference | |
| Cook et al. (1982) | |
| Rocks & Minerals: 70 (5) +2 other references |
| Rocks & Min 70:5 pp 320-333 | |
| Howard (1987) +1 other reference |
| Rocks and Minerals (1988) |
| Rocks & Min.:64:297-298. |
| Smith (1988) |
| Jason Smith & M.E. Ciriotti (2005) |
| Rocks & Minerals 54:4 pp161-165 |
| Nichael Swanson |
| SEM/EDS analyzed by Lloyd W. Alexander ... +1 other reference |
| Dana 6: 1083. |
| Sherwood et al. (1998) |
| Castor et al. (2004) |
| Rocks & Minerals | |
| Jensen et al. (2001) |
| Rocks & Min.: 17:250. +1 other reference |
| Meyers et al. (1956) |
| USGS Prof Paper 353 +3 other references | |
| Thompson et al. (2022) |
| Meyers et al. (1956) +1 other reference |
| Manchester (1931) |
| Jerry Cone Collection |
| Northrop et al. (1996) | |
| Min Rec 26:5 p483 +2 other references |
| Northrop et al. (1996) | |
| Northrop et al. (1996) |
| Northrop et al. (1996) | |
| Genth |
| Wilson et al. (1978) |
| Jason Smith collection |
| Loomis (2011) |
| Campbell et al. (1985) |
| Loomis (2011) |
| USGS Bull 380D |
| Rocks & Minerals: 67 (6) |
| USGS Prof Paper 297B | |
| Travis A. Paris (2011) |
| Edwin B (1938) +1 other reference |
| Watson (1907) +1 other reference |
| Rocks&Min. 47:594 (1972) |
| Cannon (1975) |
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Bel Air Mine, La Chapelle-Largeau, Mauléon, Bressuire, Deux-Sèvres, Nouvelle-Aquitaine, France