Dufrenite Mineral Data

General Dufrenite Information

Chemical Formula:

Fe++Fe+++4(PO4)3(OH)5•2(H2O)

Composition:

Molecular Weight = 685.22 gm

Iron 40.75 % Fe 10.49 % FeO / 46.61 % Fe₂O₃

Phosphorus 13.56 % P 31.07 % P₂O₅

Hydrogen 1.32 % H 11.83 % H₂O

Oxygen 44.36 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Fe³⁺₄(PO₄)₃(OH)₅•2(H₂O)

Environment:

Secondary mineral.

IMA Status:

Valid Species (Pre-IMA) 1833

Locality:

Anglar, Haute-Vienne, Limousin, France Link to MinDat.org Location Data.

Name Origin:

Named for Armand Small Dufrenoy (1792-1857), French mineralogist and geologist.

Name Pronunciation:

Dufrenite + Pronunciation

Synonym:

ICSD 34830

PDF 22-1143

Dufrenite Image

Images:

Dufrenite

Comments: Dark olive-greenish crystal of dufrenite on matrix.
Location: Rengersdorf, GÃ¶rlitz, Oberlausitz, Saxony, Germany. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Dufrenite Crystallography

Axial Ratios:

a:b:c =5.0409:1:2.6882

Cell Dimensions:

a = 25.84, b = 5.126, c = 13.78, Z = 4; beta = 111.2° V = 1,701.72 Den(Calc)= 2.67

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.151(1), 5.002(0.9), 12(0.9),

Physical Properties of Dufrenite

Cleavage:

{???} Perfect, {???} Distinct

Color:

Brown, Greenish brown, Green black, Dark green, Olive green.

Density:

3.2 - 3.4, Average = 3.3

Diaphaneity:

Subtranslucent to opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

3.5-4 - Copper Penny-Fluorite

Luminescence:

Non-fluorescent.

Luster:

Silky

Streak:

green

Optical Properties of Dufrenite

Gladstone-Dale:

CI meas= 0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.218 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.321,KPDmeas= 0.2597,KC= 0.2636
Ncalc = 1.7 - 1.9

Optical Data:

Biaxial (+/-), a=1.82-1.842, b=1.83-1.85, g=1.875-1.925, bire=0.0550-0.0830, 2V(Calc)=38-52, 2V(Meas)=0-90. Dispersion relatively strong.

Calculated Properties of Dufrenite

Electron Density:

Bulk Density (Electron Density)=3.24 gm/cc
note: Specific Gravity of Dufrenite =3.30 gm/cc.

Fermion Index:

Fermion Index = 0.0088542214
Boson Index = 0.9911457786

Photoelectric:

PE_Dufrenite= 12.78 barns/electron
U=PE_Dufrenite x rElectron Density= 41.37 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Dufrenite is Not Radioactive

Dufrenite Classification

Dana Class:

42.09.01.02 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.09)where (A)3 (XO4)2 Zq ï¿½ x(H2O)

(42.09.01)Burangaite Group

42.09.01.01 Burangaite (Na,Ca)2(Fe,Mg)2Al10(PO4)8(OH,O)12•4(H2O) C 2/c 2/m

42.09.01.02 Dufrenite FeFe4(PO4)3(OH)5•2(H2O) C 2/c 2/m

42.09.01.03 Natrodufrenite Na(Fe,Fe)(Fe,Al)5(PO4)4(OH)6•2(H2O) C 2/c 2/m

42.09.01.04 IMA2008-056! NaMnFe5(PO4)4(OH)6•2H2O C 2/c 2/m

42.09.01.05 Matioliite! NaMgAl5(PO4)4(OH)6•2H2O C 2/c 2/m

Strunz Class:

08.DK.15 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DK -With large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1

08.DK.15 Dufrenite FeFe4(PO4)3(OH)5•2(H2O) C 2/c 2/m

08.DK.15 Burangaite (Na,Ca)2(Fe,Mg)2Al10(PO4)8(OH,O)12•4(H2O) C 2/c 2/m

08.DK.15 Natrodufrenite Na(Fe,Fe)(Fe,Al)5(PO4)4(OH)6•2(H2O) C 2/c 2/m

08.DK.15 Matioliite! NaMgAl5(PO4)4(OH)6•2H2O C 2/c 2/m

08.DK.15 IMA2008-056! NaMnFe5(PO4)4(OH)6•2H2O C 2/c 2/m

Other Dufrenite Information

References:

NAME( Dana7) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Dufrenite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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Print or Cut-and-Paste your Dufrenite Specimen Label here :

Dufrenite

Fe++Fe+++4(PO4)3(OH)5•2(H2O)
Dana No: 42.09.01.02 Strunz No: 08.DK.15
Locality:

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