Mineralogy Database

Sillenite Mineral Data

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General Sillenite Information

Help on Chemical  Formula: Chemical Formula: Bi12SiO20
Help on Composition: Composition: Molecular Weight = 2,855.84 gm
   Silicon   0.98 %  Si    2.10 % SiO2
   Bismuth  87.81 %  Bi   97.90 % Bi2O3
   Oxygen   11.20 %  O
           ______        ______ 
           100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Bi12SiO20
Help on Environment: Environment: Associated with bismutite
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1943
Help on Locality: Locality: Durango, Mexico. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named fo rLars Gunnar Sillen (1916-1970) of Stockholm, Sweden for his work on Bi2O3 polymorphs.
Help on Name Pronunciation: Name Pronunciation: Sillenite + Pronunciation Say SILLENITE
Help on Synonym: Synonym: ICSD 28443
  PDF 37-485

Sillenite Image

Click Here for Larger   Image in a New Browser Window Images:
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Comments: Greenish to yellowish grains of sillÊnite in matrix.
Location: Schneeberg District, Erzgebirge, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Sillenite Crystallography

Help on Cell Dimensions: Cell Dimensions: a = 10.184, Z = 2; V = 1,056.22 Den(Calc)= 8.98
Help on Crystal System: Crystal System: Isometric - Tetartoidal H-M Symbol (2 3) Space Group: I 23
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.22(1), 1.74(0.9), 2.73(0.8),

Physical Properties of Sillenite

Help on Color: Color: Brownish green, Green, Gray green, Yellow green, Olive green.
Help on Density: Density: 9.3
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Habit: Habit: Cubic Crystals - Occurs as cubic shaped crystals.
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Hardness: Hardness: 1-2 - Between Talc and Gypsum
Help on Streak: Streak: gray green

Optical Properties of Sillenite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.046 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.084 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.167,KPDmeas= 0.1613,KC= 0.1542
Ncalc = 2.38 - 2.43
Help on Optical Data: Optical Data: Isotropic, n=2.5.

Calculated Properties of Sillenite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=7.62 gm/cc
note: Specific Gravity of Sillenite =9.30 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0005139279
Boson Index = 0.9994860721
Help on Photoelectric: Photoelectric: PESillenite =1,724.73 barns/electron
U=PESillenite x rElectron Density=13142.72 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Sillenite is Not Radioactive

Sillenite Classification

Help on  Dana Class: Dana Class: (04)Simple Oxides
  (04.03)with a cation charge of 3+ (A+++2 O3)
  (04.03.12)Dana Group Sillenite Bi12SiO20 I 23 2 3
Help on  Strunz Class: Strunz Class: 04.CB.70 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.C - Metal:Oxygen = 2:3, 3:5, and Similar
  04.CB -With medium-sized cations
04.CB.70 Sillenite Bi12SiO20 I 23 2 3

Other Sillenite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Sillenite :
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

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Dana No: Strunz No: 04.CB.70





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