Mineralogy Database

Ottrelite Mineral Data

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General Ottrelite Information

Help on Chemical  Formula: Chemical Formula: (Mn,Fe++,Mg)2Al4Si2O10(OH)4
Help on Composition: Composition: Molecular Weight = 490.11 gm
   Magnesium   2.48 %  Mg    4.11 % MgO
   Manganese  10.09 %  Mn   13.03 % MnO
   Aluminum   21.47 %  Al   40.57 % Al2O3
   Iron        7.98 %  Fe    8.80 % FeO /  1.63 % Fe2O3
   Silicon    11.46 %  Si   24.52 % SiO2
   Hydrogen    0.82 %  H     7.35 % H2O
   Oxygen     45.70 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mn2+0.9Fe2+0.6Mg0.5Al3.9Fe3+0.1Si2O10(OH)4
Help on Environment: Environment: Formed under non-shearing stress conditions in veins and cavities within low- to medium-grade metamorphic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1819
Help on Locality: Locality: In Belgium, in the Ardennes Mountains, from Ottre, Salmchateau, and Veilsalm. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Name Pronunciation: Name Pronunciation: Ottrelite + Pronunciation Say OTTRELITE

Ottrelite Image

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Comments: Dark green crystalline ottrelite in quartz.
Location: Vielsalm, Luxembourg, Belgium. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Ottrelite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.7332:1:3.3212
Help on Cell Dimensions: Cell Dimensions: a = 9.505, b = 5.484, c = 18.214, Z = 4; beta = 101.767° V = 929.46 Den(Calc)= 3.50
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.46(1), 2.973(0.8), 2.686(0.45),1.585(0.4), 2.439(0.4), 2.461(0.25), 2.375(0.2),

Physical Properties of Ottrelite

Help on Cleavage: Cleavage: {001} Perfect, {110} Indistinct
Help on Color: Color: Pistachio green.
Help on Density: Density: 3.52
Help on Diaphaneity: Diaphaneity: Translucent
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Habit: Habit: Scaly - Morphology like fish scales.
Help on Hardness: Hardness: 6-7 - Orthoclase-Quartz
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: greenish gray

Optical Properties of Ottrelite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.051 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.046 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2057,KPDmeas= 0.2045,KC= 0.2155
Ncalc = 1.75 - 1.76
Help on Optical Data: Optical Data: Biaxial (+), a=1.709-1.725, b=1.712-1.726, g=1.716-1.732, bire=0.0070, 2V(Calc)=46-82, 2V(Meas)=46-70. Dispersion r > v strong.
Help on Pleochroism (x): Pleochroism (x): olive yellow.
Help on Pleochroism (y): Pleochroism (y): pale greenish yellow.
Help on Pleochroism (z): Pleochroism (z): very light yellow.

Calculated Properties of Ottrelite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.45 gm/cc
note: Specific Gravity of Ottrelite =3.50 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0097433358
Boson Index = 0.9902566642
Help on Photoelectric: Photoelectric: PEOttrelite = 6.03 barns/electron
U=PEOttrelite x rElectron Density= 20.79 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Ottrelite is Not Radioactive

Ottrelite Classification

Help on  Dana Class: Dana Class: (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O
  (52.03)with cations in [6] coordination only
  (52.03.03)Chloritoid group Chloritoid (Fe,Mg,Mn)2Al4Si2O10(OH)4 P1 1 Magnesiochloritoid MgAl2SiO5(OH)2 C 2/c 2/m Ottrelite (Mn,Fe,Mg)2Al4Si2O10(OH)4 C 2/c 2/m Carboirite-VIII Fe(Al,Ge)2O[(Ge,Si)O4](OH)2 C1 1
Help on  Strunz Class: Strunz Class: 09.AF.85 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AF -Nesosilicates with additional anions;
09.AF.85 Chloritoid (Fe,Mg,Mn)2Al4Si2O10(OH)4 P1 1
09.AF.85 Magnesiochloritoid MgAl2SiO5(OH)2 C 2/c 2/m
09.AF.85 Ottrelite (Mn,Fe,Mg)2Al4Si2O10(OH)4 C 2/c 2/m

Other Ottrelite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)
Help on See Also: See Also: Links to other databases for Ottrelite :
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: 09.AF.85





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