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 % P₂O₅

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⁺_1.5Mn²⁺_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

Comments: Brown zwieselite in granite pegmatite.
Location: Sauberg Mine, Ehrenfriedersdorf, Erzgebirge, Saxony, Germany. Scale: Specimen size 9 mm.
© Thomas Witzke / Abraxas-Verlag

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

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

By Intensity(I/I_o): 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:

PE_Zwieselite= 15.18 barns/electron
U=PE_Zwieselite x rElectron 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 ï¿½ 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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Print or Cut-and-Paste your Zwieselite Specimen Label here :

Zwieselite

(Fe++,Mn)2(PO4)F
Dana No: 41.06.01.01 Strunz No: 08.BB.10
Locality:

Notes:

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