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Howieite Mineral Data

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General Howieite Information

Help on Chemical  Formula: Chemical Formula: Na(Fe++,Mn++)10(Fe,Al)2Si12O31(OH)13
Help on Composition: Composition: Molecular Weight = 2,544.93 gm
   Sodium      0.90 %  Na    1.22 % Na2O
   Magnesium   0.48 %  Mg    0.79 % MgO
   Manganese   6.48 %  Mn    8.36 % MnO
   Aluminum    0.64 %  Al    1.20 % Al2O3
   Iron       17.56 %  Fe   18.07 % FeO /  5.02 % Fe2O3
   Silicon    26.49 %  Si   56.66 % SiO2
   Hydrogen    0.50 %  H     4.50 % H2O
   Oxygen     46.96 %  O
             ______        ______ 
             100.00 %       95.82 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: NaFe2+6.4Mn2+3Mg0.5Fe3+1.6Al0.62(Si12)2(O31)(OH)12.7
Help on Environment: Environment: In the Jurassic-aged Franciscan Formation metamorphosed to blue-shist facies (high pressure, low temperature ).
Help on IMA Status: IMA Status: Approved IMA 1964
Help on Locality: Locality: Laytonville quarry, 5 miles south of Laytonville, Mendocino Co. California. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Robert Andrew Howie (1923-), British mineralogist and petrologist, King's College, London University, UK.
Help on Name Pronunciation: Name Pronunciation: Howieite Say HOWIEITE
Help on Synonym: Synonym: ICSD 6257
  PDF 19-571

Howieite Image

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Comments: Black vitreous radiating crystalline howieite.
Location: Longvale Quarry, Mendocino County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Howieite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.0405:1:0.981
Help on Cell Dimensions: Cell Dimensions: a = 10.17, b = 9.774, c = 9.589, Z = 1; alpha = 91.22°, beta = 70.76°, gamma = 108.09° V = 855.25 Den(Calc)= 4.94
Help on Crystal System: Crystal System: Triclinic Space Group: P1,P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 9.18(1), 7.91(0.8), 3.25(0.65),

Physical Properties of Howieite

Help on Cleavage: Cleavage: {010} Good, {100} Distinct, {210} Poor
Help on Color: Color: Dark green, Black.
Help on Density: Density: 3.378
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Habit: Habit: Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).
Help on Luster: Luster: Greasy (Oily)
Help on Streak: Streak: grayish black

Optical Properties of Howieite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.033 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.296 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1448,KPDmeas= 0.2127,KC= 0.2058
Ncalc = 1.7 - 2.02
Help on Optical Data: Optical Data: Biaxial (-), a=1.701, b=1.72, g=1.734, bire=0.0330, 2V(Calc)=80, 2V(Meas)=65.
Help on Pleochroism (x): Pleochroism (x): golden yellow.
Help on Pleochroism (y): Pleochroism (y): dark lilac green.
Help on Pleochroism (z): Pleochroism (z): green.

Calculated Properties of Howieite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.33 gm/cc
note: Specific Gravity of Howieite =3.38 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEHowieite = 7.90 barns/electron
U=PEHowieite x rElectron Density= 26.31 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Howieite is Not Radioactive

Howieite Classification

Help on  Dana Class: Dana Class: (69)Inosilicate Chains with Side Branches or Loops
  (69.02)with P>2
  (69.02.03)Howieite group Howieite Na(Fe,Mn)10(Fe,Al)2Si12O31(OH)13 P1,P1 Tri Taneyamalite (Na,Ca)(Mn,Mg)12[(Si,Al)6O17]2(O,OH)10 P1 1 Deerite (Fe,Mn)6(Fe,Al)3Si6O20(OH)5 P 21/a 2/m
Help on  Strunz Class: Strunz Class: 09.DH.65 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DH -Inosilicates with 4-periodic single chains, Si4O12
09.DH.65 Howieite Na(Fe,Mn)10(Fe,Al)2Si12O31(OH)13 P1,P1 Tri
09.DH.65 Taneyamalite (Na,Ca)(Mn,Mg)12[(Si,Al)6O17]2(O,OH)10 P1 1

Other Howieite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)
Help on See Also: See Also: Links to other databases for Howieite :
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.DH.65





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