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 - PrismaticH-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),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Moore P B , American Mineralogist , 55 (1970) p.135-169, Crystal chemistry of the basic iron phosphates

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 · 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

Search for Dufrenite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Dufrenite :

A Bijoux Google Search for Dufrenite
Adam's Minerals Google Search for Dufrenite
Cape Minerals Google Search for Dufrenite
Dakota Matrix Minerals Google Search for Dufrenite
Excalibur Mineral Corp. Google Search for Dufrenite
Exceptional Minerals Google Search for Dufrenite
John Betts Fine Minerals Search for Dufrenite
McDougall Minerals Google Search for Dufrenite
Mineral News Website Link
Rock and Mineral Shows Google Search for Dufrenite
Weinrich Minerals, Inc. Google Search for Dufrenite

Ask about Dufrenite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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:

Notes: