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Bementite Mineral Data

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General Bementite Information

Help on Chemical  Formula: Chemical Formula: Mn8Si6O15(OH)10
Help on Composition: Composition: Molecular Weight = 1,018.08 gm
   Manganese  43.17 %  Mn   55.74 % MnO
   Silicon    16.55 %  Si   35.41 % SiO2
   Hydrogen    0.99 %  H     8.85 % H2O
   Oxygen     39.29 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mn2+8Si6O15(OH)10
Help on Environment: Environment: Metamorphosed zinc deposit.
Help on IMA Status: IMA Status: Approved IMA 1963
Help on Locality: Locality: Franklin, Sussex Co., New Jersey. USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: For Clarence Sweet Bement (1843-1923), mineral collector of Philadelphia, Pennsylvania, USA.
Help on Name Pronunciation: Name Pronunciation: Bementite + Pronunciation Say BEMENTITE

Bementite Image

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Comments: Brown massive bementite.
Location: Olympic Mountains, Washington, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bementite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.8438:1:0.8359
Help on Cell Dimensions: Cell Dimensions: a = 14.838, b = 17.584, c = 14.7, Z = 7; beta = 95.54° V = 3,817.48 Den(Calc)= 3.10
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.3(1), 2.51(0.9), 2.81(0.7),

Physical Properties of Bementite

Help on Cleavage: Cleavage: {???} Perfect, {???} Good, {???} Good
Help on Color: Color: Brown, Gray, Yellow, Yellow brown, Pink.
Help on Density: Density: 2.98
Help on Diaphaneity: Diaphaneity: Translucent to subtranslucent
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Habit: Habit: Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: yellow white

Optical Properties of Bementite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.007 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.046 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2038,KPDmeas= 0.212,KC= 0.2135
Ncalc = 1.64 - 1.66
Help on Optical Data: Optical Data: Biaxial (?), a=1.602-1.624, b=1.632-1.65, g=1.632-1.65, bire=0.0260-0.0300

Calculated Properties of Bementite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.89 gm/cc
note: Specific Gravity of Bementite =2.98 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0079198565
Boson Index = 0.9920801435
Help on Photoelectric: Photoelectric: PEBementite = 11.66 barns/electron
U=PEBementite x rElectron Density= 33.72 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Bementite is Not Radioactive

Bementite Classification

Help on  Dana Class: Dana Class: (78)Unclassified silicates
  (78.05)possible phyllosilicates
  (78.05.02)Dana Group Bementite Mn8Si6O15(OH)10 P 21/c 2/m
Help on  Strunz Class: Strunz Class: 09.EE.05 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EE -Single tetrahedral nets of 6-membered rings
09.EE.05 Bementite Mn8Si6O15(OH)10 P 21/c 2/m

Other Bementite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Bementite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - Franklin Minerals(Palache)
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

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Dana No: Strunz No: 09.EE.05





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