Zwieselite Mineral Data
General Zwieselite Information
Chemical Formula:
(Fe++,Mn)2(PO4)F
Composition:
Molecular Weight = 225.21 gm
Manganese 12.20 % Mn 15.75 % MnO
Iron 37.20 % Fe 47.85 % FeO
Phosphorus 13.75 % P 31.51 % P2 O5
Oxygen 28.42 % O
Fluorine 8.44 % F 8.44 % F
- %
F -3.55 % -O=F2
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Fe2+ 1.5 Mn2+ 0.5 (PO4 )F
Environment:
Forms a series with triplite (Fe) and magniotriplite (Mg).
IMA Status:
Valid Species (Pre-IMA) 1841
Locality:
Rebenstein, Zweisel, Bavaria, Germany. Link to MinDat.org Location Data.
Name Origin:
Named for the locality.
Name Pronunciation:
Zwieselite + Pronunciation
Synonym:
ICSD 4428
PDF 21-811
Zwieselite Image
Images:
Zwieselite Crystallography
Axial Ratios:
a:b:c =1.8687:1:1.5339
Cell Dimensions:
a = 12.046, b = 6.446, c = 9.888, Z = 8; beta = 107.42° V = 732.57 Den(Calc)= 4.08
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: I2/a
X Ray Diffraction:
By Intensity(I/Io ): 2.86(1), 3.03(0.9), 3.2(0.7), 3.6(0.5), 2.12(0.4), 3.38(0.4), 2.59(0.3),
Physical Properties of Zwieselite
Cleavage:
{001} Good, {010} Distinct, {100} Indistinct
Color:
Dark brown, Black, Black brown.
Density:
3.927 - 3.97, Average = 3.94
Diaphaneity:
Translucent
Fracture:
Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.
Habit:
Pseudo Cubic - Crystals show a cubic outline.
Hardness:
5-5.5 - Apatite-Knife Blade
Luster:
Vitreous - Resinous
Streak:
white
Optical Properties of Zwieselite
Gladstone-Dale:
CI meas = 0.039 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = 0.07 (Fair) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.1699,KPDmeas = 0.1755,KC = 0.1826 Ncalc = 1.72 - 1.75
Optical Data:
Biaxial (+), a=1.686, b=1.69, g=1.703, bire=0.0170, 2V(Calc)=60, 2V(Meas)=58.
Calculated Properties of Zwieselite
Electron Density:
Bulk Density (Electron Density)=3.77 gm/cc note: Specific Gravity of Zwieselite =3.95 gm/cc.
Fermion Index:
Fermion Index = 0.0080221089 Boson Index = 0.9919778911
Photoelectric:
PEZwieselite = 15.18 barns/electronU=PEZwieselite x r Electron Density= 57.22 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Zwieselite is Not Radioactive
Zwieselite Classification
Dana Class:
41.06.01.01 (41) Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen
(41.06) where (A)2 (XO4) Zq
(41.06.01) Zwieselite Group
41.06.01.01 Zwieselite (Fe,Mn)2(PO4)F I2/a 2/m
41.06.01.02 Triplite (Mn,Fe,Mg,Ca)2(PO4)(F,OH) I2/m 2/m
41.06.01.03 Magniotriplite ? (Mg,Fe,Mn)2(PO4)F P 21 /a 2/m
Strunz Class:
08.BB.10 08 - PHOSPHATES, ARSENATES, VANADATES
08.B - Phosphates, etc. with Additional Anions, without H2O
08.BB -With only medium-sized cations, (OH, etc.):RO4 � 1:1
08.BB.10 Magniotriplite ? (Mg,Fe,Mn)2(PO4)F P 21 /a 2/m
08.BB.10 Hydroxylwagnerite ! Mg2(PO4)(OH) P 21 /c 2/m
08.BB.10 Triplite (Mn,Fe,Mg,Ca)2(PO4)(F,OH) I2/m 2/m
08.BB.10 Zwieselite (Fe,Mn)2(PO4)F I2/a 2/m
Other Zwieselite Information
References:
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Zwieselite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST
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Zwieselite
(Fe++,Mn)2(PO4)F
Dana No: 41.06.01.01 Strunz No: 08.BB.10
Locality:
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