Mineralogy Database

Pyrophyllite Mineral Data

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General Pyrophyllite Information

Help on Chemical  Formula: Chemical Formula: Al2Si4O10(OH)2
Help on Composition: Composition: Molecular Weight = 360.31 gm
   Aluminum  14.98 %  Al   28.30 % Al2O3
   Silicon   31.18 %  Si   66.70 % SiO2
   Hydrogen   0.56 %  H     5.00 % H2O
   Oxygen    53.28 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Al2Si4O10(OH)2
Help on Environment: Environment: Somewhat uncommon, found both in hydrothermal veins and in bedded deposits in schistose metamorphic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1829
Help on Locality: Locality: Tres Cerritos, California, USA; Pyschminsk and Beresovsk, Ural Mountains, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek for fie and leaf, in allusion to its tendency to exfoliate into fan shapes when heated.
Help on Name Pronunciation: Name Pronunciation: Pyrophyllite + Pronunciation Say PYROPHYLLITE
 

Pyrophyllite Image

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  Rutile   Pyrophyllite

Comments: Rutile on fine-grained pyrophyllite.
Location: Graves Mt. Georgia, USA. Scale: 4.5 x 5 cm.
© Fabre Minerals

Pyrophyllite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5761:1:1.0439
Help on Cell Dimensions: Cell Dimensions: a = 5.161, b = 8.957, c = 9.351, Z = 2; alpha = 91.03°, beta = 100.37°, gamma = 89.75° V = 425.14 Den(Calc)= 2.81
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.42(1), 9.2(0.9), 3.07(0.85),
 

Physical Properties of Pyrophyllite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Brown green, Brownish yellow, Greenish, Gray green, Gray white.
Help on Density: Density: 2.8 - 2.9, Average = 2.84
Help on Diaphaneity: Diaphaneity: Translucent to opaque
Help on Fracture: Fracture: Flexible - Flexible fragments.
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Hardness: Hardness: 1.5-2 - Talc-Gypsum
Help on Luminescence: Luminescence: Fluorescent, Long UV=butter yellow.
Help on Luster: Luster: Pearly
Help on Streak: Streak: white
 

Optical Properties of Pyrophyllite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.055 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2053,KPDmeas= 0.2025,KC= 0.2143
Ncalc = 1.6 - 1.62
Help on Optical Data: Optical Data: Biaxial (-), a=1.534-1.556, b=1.586-1.589, g=1.596-1.601, bire=0.0450-0.0620, 2V(Calc)=46-60, 2V(Meas)=53-62. Dispersion none.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
 

Calculated Properties of Pyrophyllite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.81 gm/cc
note: Specific Gravity of Pyrophyllite =2.81 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEPyrophyllite = 1.65 barns/electron
U=PEPyrophyllite x rElectron Density= 4.62 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Pyrophyllite is Not Radioactive
 

Pyrophyllite Classification

Help on  Dana Class: Dana Class: 71.02.01.01 (71)Phyllosilicate Sheets of Six-Membered Rings
  (71.02)with 2:1 Layers
  (71.02.01)Pyrophyllite-talc group
 
71.02.01.01 Pyrophyllite Al2Si4O10(OH)2 P1 1
 
71.02.01.02 Ferripyrophyllite Fe2Si4O10(OH)2 C 2/m 2/m
 
71.02.01.03 Talc Mg3Si4O10(OH)2 C 2/c 2/m
 
71.02.01.04 Willemseite (Ni,Mg)3Si4O10(OH)2 C 2/c 2/m
 
71.02.01.05 Minnesotaite (Fe,Mg)3Si4O10(OH)2 C1 1
 
71.02.01.06 Brinrobertsite! (Na,K,Ca)x(Al,Fe,Mg)4(Si,Al)8O20(OH)4•3.54(H2O)[x=0.35,n=3.54] pseudo 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.EC.10 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
 
09.EC.10 Ferripyrophyllite Fe2Si4O10(OH)2 C 2/m 2/m
 
09.EC.10 Pyrophyllite Al2Si4O10(OH)2 P1 1
 

Other Pyrophyllite Information

Help on See Also: See Also: Links to other databases for Pyrophyllite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - HyperPhysics
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - Scandinavian mineral gallery
16 - WWW-MINCRYST

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

Pyrophyllite

Al2Si4O10(OH)2
Dana No: 71.02.01.01 Strunz No: 09.EC.10
Locality:

 

Notes:

 

 


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