Sillimanite Mineral Data

Sillimanite Mineral Data
Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images       News Help About


NY NJ Expos

[How the Club Works] [Memberships - Junior, Deluxe , and Platinum] [FAQ] [Past Minerals]
Join the Club - Junior, Deluxe and Platinum Memberships Available
High Quality Minerals Sent to Your Home or School Each Month
Mineral of the Month Club - An Inexpensive Way to Enjoy Minerals

Wrights Rock Shop

General Sillimanite Information

Help on Chemical Formula: Chemical Formula: Al2SiO5 = Al[6]Al[4]OSiO4
Help on Composition: Composition: Molecular Weight = 162.05 gm
   Aluminum  33.30 %  Al   62.92 % Al2O3
   Silicon   17.33 %  Si   37.08 % SiO2
   Oxygen    49.37 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: (Al2O3)(SiO2)
Help on Environment: Environment: Metamorphosed peri-aluminous sedimentary rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1824
Help on Locality: Locality: Wide spread world wide occurrences. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the American chemist and mineralogist, B. Silliman (1779-1824).
Help on Name Pronunciation: Name Pronunciation: Sillimanite + Pronunciation Say SILLIMANITE
Help on Synonym: Synonym: Fibrolite
  ICSD 100450
  PDF 38-471
 

Sillimanite Image

Click Here for Larger Sillimanite Image in a New Browser Window Images:
Click Here for Larger Sillimanite Image

Sillimanite

Comments: Silky massive sillimanite.
Location: Khasia Hills, Assum, India. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Sillimanite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.9754:1:0.752
Help on Cell Dimensions: Cell Dimensions: a = 7.484, b = 7.672, c = 5.77, Z = 4; V = 331.30 Den(Calc)= 3.25
Help on Crystal System: Crystal System: Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: P nma
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.42(1), 3.37(0.65), 2.2(0.6),
Help on Forms: Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: ( 1 2 0) ( 2 1 0) ( 1 1 0) ( 1 0 0) ( 0 0 1)

Warning: this large pop-up is very compute intensive and may not work well with some computers.
Click Here for Large Sillimanite Structure Window 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


Winter J K , Ghose S , American Mineralogist , 64 (1979) p.573-586, Thermal expansion and high-temperature crystal chemistry of the Al2SiO5, polymorphs, T = 25 deg C

View Additional jPOWD Structure files for Sillimanite
[1] [10] [11] [12] [13] [14] [15] [16] [2] [3] [4] [5] [6] [7] [8] [9]
 

Physical Properties of Sillimanite

Help on Cleavage: Cleavage: {010} Perfect
Help on Color: Color: Bluish, Brownish greenish, Colorless, Gray, Gray green.
Help on Density: Density: 3.24
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Splintery - Thin, elongated fractures produced by intersecting good cleavages or partings (e.g. hornblende).
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 7 - Quartz
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Sillimanite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.01 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.013 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2047,KPDmeas= 0.2053,KC= 0.2074
Ncalc = 1.67
Help on Optical Data: Optical Data: Biaxial (+), a=1.653-1.661, b=1.654-1.67, g=1.669-1.684, bire=0.0160-0.0230, 2V(Calc)=30-80, 2V(Meas)=20-30. Dispersion strong, r > v.
Help on Pleochroism (x): Pleochroism (x): colorless, pale brown, or yellow.
Help on Pleochroism (y): Pleochroism (y): colorless, brown, or grayish green.
 

Calculated Properties of Sillimanite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.20 gm/cc
note: Specific Gravity of Sillimanite =3.24 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0083309363
Boson Index = 0.9916690637
Help on Photoelectric: Photoelectric: PESillimanite = 1.64 barns/electron
U=PESillimanite x rElectron Density= 5.24 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Sillimanite is Not Radioactive
 

Sillimanite Classification
Help on Dana Class: Dana Class: 52.02.02a.01 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O
  (52.02)with cations in [4] and >[4] coordination
  (52.02.02a)Al2SiO5 (Sillimanite subgroup)
 
52.02.02a.01 Sillimanite Al2SiO5=Al[6]Al[4]OSiO4 P nma 2/m 2/m 2/m
 
52.02.02a.02 Mullite Al(42x)Si(2-2x)O(10-x)wherex=0.17to0.59 Pbam 2/m 2/m 2/m
 
52.02.02a.03 Boromullite! Al4.5SiB0.5O9.5 C mc21 mm2
Help on Strunz Class: Strunz Class: 09.AF.05 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AF -Nesosilicates with additional anions;
 
09.AF.05 Sillimanite Al2SiO5=Al[6]Al[4]OSiO4 P nma 2/m 2/m 2/m
 

Other Sillimanite Information
Help on See Also: See Also: Links to other databases for Sillimanite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - CalTech Mineral Spectroscopy
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - Franklin Minerals(Dunn)
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - HyperPhysics
14 - MinDAT
15 - Mineralienatlas (Deutsch)
16 - Minerals in Thin Sections-Humboldt State
17 - Online Mineral Museum
18 - QUT Mineral Atlas
19 - Ruff.Info
20 - Scandinavian mineral gallery
21 - UCLA - Petrography Thin-Sections
22 - University of Colorado - Mineral Structure Data
23 - WWW-MINCRYST
24 - YupRocks

Search for Sillimanite using:

Google
 
Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Sillimanite :

B and L Fine Minerals
Dakota Matrix Minerals
Dan & Diana Weinrich Mineral Auctions
Excalibur Mineral Corp.
Exceptional Minerals
John Betts Fine Minerals
Mineral News
Mineral of the Month Club
NY/NJ Gem & Mineral Show
TIMA Mineral Analyzer
Weinrich Minerals, Inc.
Wright's Rock Shop

Ask about Sillimanite 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 Espaņol

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

Sillimanite

Al2SiO5 = Al[6]Al[4]OSiO4
Dana No: 52.02.02a.01 Strunz No: 09.AF.05
Locality:

 

Notes: