Preiswerkite Mineral Data

General Preiswerkite Information

Chemical Formula:

NaMg2Al3Si2O10(OH)2

Composition:

Molecular Weight = 402.72 gm

Sodium 5.71 % Na 7.69 % Na₂O

Magnesium 12.07 % Mg 20.02 % MgO

Aluminum 20.10 % Al 37.98 % Al₂O₃

Silicon 13.95 % Si 29.84 % SiO₂

Hydrogen 0.50 % H 4.47 % H₂O

Oxygen 47.67 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaMg₂Al₃Si₂O₁₀(OH)₂

Environment:

Formed in a rodingite dike during upper-greenschist to lower-amphibolite facies metamorphism.

IMA Status:

Approved IMA 1980

Locality:

In the Geisspfad ultramafic complex, Binntal, Valais, Switzerland. Link to MinDat.org Location Data.

Name Origin:

Named for H. Preiswerk (1876-1940), Professor in Basel, Switzerland.

Name Pronunciation:

Preiswerkite + Pronunciation

Preiswerkite Image

Images:

Preiswerkite

Comments: Pale green fine grained preiswerkite masses in dark amphibolite rock.
Location: Geisspfad, Binnental, Valias, Switzerland. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Preiswerkite Crystallography

Axial Ratios:

a:b:c =0.5777:1:1.085

Cell Dimensions:

a = 5.228, b = 9.049, c = 9.819, Z = 2; beta = 100.42° V = 456.86 Den(Calc)= 2.93

Crystal System:

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

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

By Intensity(I/I_o): 1.503(1), 2.572(1), 2.457(0.7),

Physical Properties of Preiswerkite

Cleavage:

{001} Perfect

Color:

Greenish white, Light green.

Density:

2.96

Diaphaneity:

Transparent to Translucent

Hardness:

2.5 - Finger Nail

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Preiswerkite

Gladstone-Dale:

CI meas= 0.043 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.033 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2035,KPDmeas= 0.2015,KC= 0.2105
Ncalc = 1.62

Optical Data:

Biaxial (-), a=1.56, b=1.614, g=1.615, bire=0.0550, 2V(Calc)=14, 2V(Meas)=5-7.

Calculated Properties of Preiswerkite

Electron Density:

Bulk Density (Electron Density)=2.91 gm/cc
note: Specific Gravity of Preiswerkite =2.93 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Preiswerkite= 1.49 barns/electron
U=PE_Preiswerkite x rElectron Density= 4.33 barns/cc.

Radioactivity:

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

Preiswerkite Classification

Dana Class:

71.02.02b.15 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.02)with 2:1 Layers

(71.02.02b)Mica Group (Biotite subgroup)

71.02.02b.01 Phlogopite KMg3(Si3Al)O10(F,OH)2 C 2/m 2/m

71.02.02b.01a Tetraferriphlogopite! KMg3FeSi3O10(OH)2 2/m

71.02.02b.01b Shirozulite! KMn3(AlSi3)O10(OH,F)2 C 2/m 2/m

71.02.02b.01c Fluorophlogopite! KMg3(AlSi3)O10F2 C 2/m 2/m

71.02.02b.02 Biotite* K(Mg,Fe)3[AlSi3O10(OH,F)2 C 2/m 2/m

71.02.02b.03 Annite KFe3AlSi3O10(OH,F)2 C 2/m 2/m

71.02.02b.03a Fluorannite! KFe3AlSi3O10F2 C 2/m 2/m

71.02.02b.04 Tetraferriannite K(Fe,Mg)3(Fe,Al)Si3O10(OH)2 C 2/m 2/m

71.02.02b.05 Siderophyllite KFe2Al(Al2Si2)O10(F,OH)2 C 2/m 2/m

71.02.02b.05a Eastonite! KMg2Al[Al2Si2O10](OH)2 2/m

71.02.02b.06 Hendricksite K(Zn,Mg,Mn)3Si3AlO10(OH)2 C 2/m 2/m

71.02.02b.07 Lepidolite K(Li,Al)3(Si,Al)4O10(F,OH)2 C 2/m,Cm Mono

71.02.02b.08 Polylithionite KLi2AlSi4O10(F,OH)2 C 2/m 2/m

71.02.02b.08a Trilithionite! KLi1.5Al1.5AlSi3O10F2 C 2/m 2/m

71.02.02b.08b Sokolovaite! CsLi2AlSi4O10F2 C 2/m, C 2 or Cm Mono

71.02.02b.09 Tainiolite KLiMg2Si4O10F2 C 2/m 2/m

71.02.02b.10 Zinnwaldite KLiFeAl(AlSi3)O10(F,OH)2 C 2/m 2/m

71.02.02b.11 Norrishite K(Mn2Li)Si4O10(O)2 C 2/m 2/m

71.02.02b.12 Masutomilite K(Li,Al,Mn)3[(Si,Al)4O10](F,OH)2 C 2/m 2/m

71.02.02b.13 Aspidolite NaMg3AlSi3O10(OH)2 C 2/m 2/m

71.02.02b.14 Wonesite (Na,K).5(Mg,Fe,Al)3(Si,Al)4O10(OH,F)2 C 2/m 2/m

71.02.02b.15 Preiswerkite NaMg2Al3Si2O10(OH)2 C 2/m 2/m

71.02.02b.16 Ephesite NaLiAl2(Al2Si2)O10(OH)2 C 2/c 2/m

71.02.02b.18 Suhailite! (NH4)Fe3(Si3Al)O10(OH)2 C 2/m? 2/m

Strunz Class:

09.EC.20 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.20 Annite KFe3AlSi3O10(OH,F)2 C 2/m 2/m

09.EC.20 Biotite* K(Mg,Fe)3[AlSi3O10(OH,F)2 C 2/m 2/m

09.EC.20 Hendricksite K(Zn,Mg,Mn)3Si3AlO10(OH)2 C 2/m 2/m

09.EC.20 Ephesite NaLiAl2(Al2Si2)O10(OH)2 C 2/c 2/m

09.EC.20 Aspidolite NaMg3AlSi3O10(OH)2 C 2/m 2/m

09.EC.20 Lepidolite K(Li,Al)3(Si,Al)4O10(F,OH)2 C 2/m,Cm Mono

09.EC.20 Preiswerkite NaMg2Al3Si2O10(OH)2 C 2/m 2/m

09.EC.20 Masutomilite K(Li,Al,Mn)3[(Si,Al)4O10](F,OH)2 C 2/m 2/m

09.EC.20 Wonesite (Na,K).5(Mg,Fe,Al)3(Si,Al)4O10(OH,F)2 C 2/m 2/m

09.EC.20 Polylithionite KLi2AlSi4O10(F,OH)2 C 2/m 2/m

09.EC.20 Phlogopite KMg3(Si3Al)O10(F,OH)2 C 2/m 2/m

09.EC.20 Norrishite K(Mn2Li)Si4O10(O)2 C 2/m 2/m

09.EC.20 Siderophyllite KFe2Al(Al2Si2)O10(F,OH)2 C 2/m 2/m

09.EC.20 Fluorannite! KFe3AlSi3O10F2 C 2/m 2/m

09.EC.20 Shirokshinite! K(NaMg2)Si4O10F2 C 2/m 2/m

09.EC.20 Zinnwaldite KLiFeAl(AlSi3)O10(F,OH)2 C 2/m 2/m

09.EC.20 Eastonite! KMg2Al[Al2Si2O10](OH)2 2/m

09.EC.20 Tetraferriannite K(Fe,Mg)3(Fe,Al)Si3O10(OH)2 C 2/m 2/m

09.EC.20 Tetraferriphlogopite! KMg3FeSi3O10(OH)2 2/m

09.EC.20 Trilithionite! KLi1.5Al1.5AlSi3O10F2 C 2/m 2/m

09.EC.20 Sokolovaite! CsLi2AlSi4O10F2 C 2/m, C 2 or Cm Mono

09.EC.20 Shirozulite! KMn3(AlSi3)O10(OH,F)2 C 2/m 2/m

09.EC.20 Suhailite! (NH4)Fe3(Si3Al)O10(OH)2 C 2/m? 2/m

09.EC.20 Fluorophlogopite! KMg3(AlSi3)O10F2 C 2/m 2/m

Other Preiswerkite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Preiswerkite :
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 Preiswerkite Specimen Label here :

Preiswerkite

NaMg2Al3Si2O10(OH)2
Dana No: 71.02.02b.15 Strunz No: 09.EC.20
Locality:

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