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Obertiite Mineral Data

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General Obertiite Information

Help on Chemical  Formula: Chemical Formula: NaNa2(Mg3Fe+++Ti)Si8O22(O,F,OH)2
Help on Composition: Composition: Molecular Weight = 855.28 gm
   Sodium      8.06 %  Na   10.87 % Na2O
   Magnesium   8.53 %  Mg   14.14 % MgO
   Titanium    5.60 %  Ti    9.34 % TiO2
   Iron        6.53 %  Fe    9.34 % Fe2O3
   Silicon    26.27 %  Si   56.20 % SiO2
   Hydrogen    0.03 %  H     0.26 % H2O
   Oxygen     44.43 %  O
   Fluorine    0.56 %  F     0.56 % F
                -   %   F    -0.23 % -O=F2    
             ______        ______ 
             100.00 %      100.47 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na3Mg3Fe3+Ti(Si8O22)O1.5F0.25(OH)0.25
Help on Environment: Environment: In cavities with basaltic flows. A member of the anhydrous amphibole group.
Help on IMA Status: IMA Status: Approved IMA 1998 (Dana # Added)
Help on Locality: Locality: The Bellerberg quarry, Laacher See district, Eifel region, Germany. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Dr. Roberta Oberti (1951-), Pavia, Italy, for her contributions to the understanding of the crystal chemistry of the amphibole group.
Help on Synonym: Synonym: Ferric-nyboite
  IMA1998-046
 

Obertiite Image

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  Obertiite

Comments: Pinkish grains of obertiite in matrix.
Location: Bellerberg Mt., Eifel District, Rheinland-Phalz, Germany. Scale: Specimen Size 7x6 mm.
© Sergey Vasiliev / Systematic Mineralogy

Obertiite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5455:1:0.2953
Help on Cell Dimensions: Cell Dimensions: a = 9.776, b = 17.919, c = 5.292, Z = 2; beta = 104.05° V = 899.30 Den(Calc)= 3.16
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 8.414(1)(110), 2.705(0.7)(331,151), 3.39(0.6)(131),2.531(0.5)(202), 3.117(0.5)(310), 4.467(0.5)(040),
 

Physical Properties of Obertiite

Help on Cleavage: Cleavage: {110} Perfect, {110} Perfect
Help on Color: Color: Pale pink.
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).
Help on Hardness: Hardness: 5 - Apatite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Obertiite

Help on Gladstone-Dale: Gladstone-Dale: CI calc= 0.108 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2078,KC= 0.2331
Ncalc = 1.74
Help on Optical Data: Optical Data: Biaxial (-), a=1.643, b=1.657, g=1.67, bire=0.0270, 2V(Calc)=86, 2V(Meas)=81. Dispersion dispersion not observed.
 

Calculated Properties of Obertiite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.11 gm/cc
note: Specific Gravity of Obertiite =3.16 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PEObertiite = 4.17 barns/electron
U=PEObertiite x rElectron Density= 12.98 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Obertiite is Not Radioactive
 

Obertiite Classification

Help on  Dana Class: Dana Class: 66.01.03c.16 (66)Inosilicate Double-Width Unbranched Chains, W=2
  (66.01)with P=2 amphibole configuration
  (66.01.03c)Group 4, the sodic amphiboles
 
66.01.03c.01 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.02 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.03 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.04 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.05 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.06 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.07 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.08 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.09 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.09a Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m
 
66.01.03c.09b Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m
 
66.01.03c.10 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.11 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m
 
66.01.03c.11a Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m
 
66.01.03c.11b Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m
 
66.01.03c.11c Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m
 
66.01.03c.12 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m
 
66.01.03c.12a Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m
 
66.01.03c.12b Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m
 
66.01.03c.13 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m
 
66.01.03c.14 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m
 
66.01.03c.15 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m
 
66.01.03c.16 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m
 
66.01.03c.17 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.DE.25 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DE -Inosilicates with 2-periodic double chains, Si4O11; amphibole family
 
09.DE.25 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m
 
09.DE.25 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m
 
09.DE.25 Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m
 
09.DE.25 Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m
 
09.DE.25 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m
 
09.DE.25 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m
 
09.DE.25 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m
 
09.DE.25 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m
 
09.DE.25 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m
 
09.DE.25 Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m
 
09.DE.25 Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m
 
09.DE.25 Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m
 
09.DE.25 Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m
 
09.DE.25 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m
 

Other Obertiite Information

Help on References: References: NAME( MinRec, v 32, p 218) PHYS. PROP.(MinRec, v 32, p 218) OPTIC PROP.(MinRec, v 32, p 218)
Help on See Also: See Also: Links to other databases for Obertiite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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

Obertiite

NaNa2(Mg3Fe+++Ti)Si8O22(O,F,OH)2
Dana No: 66.01.03c.16 Strunz No: 09.DE.25
Locality:

 

Notes:

 

 
   
 


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