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Dumortierite Mineral Data

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General Dumortierite Information

Help on Chemical  Formula: Chemical Formula: Al6.5-7(BO3)(SiO4)3(O,OH)3
Help on Composition: Composition: Molecular Weight = 569.73 gm
   Aluminum  32.68 %  Al   61.74 % Al2O3
   Silicon   14.79 %  Si   31.64 % SiO2
   Boron      1.90 %  B     6.11 % B2O3
   Hydrogen   0.09 %  H     0.79 % H2O
   Oxygen    50.55 %  O
            ______        ______ 
            100.00 %      100.28 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Al6.9(BO3)(SiO4)3O2.5(OH)0.5
Help on Environment: Environment: Pegmatites, pneumatolytic, and metamorphic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1881
Help on Locality: Locality: San Diego Co., California. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the French paleontologist, M. E. Dumortier (1803-1873).
Help on Name Pronunciation: Name Pronunciation: Dumortierite + Pronunciation Say DUMORTIERITE
Help on Synonym: Synonym: ICSD 100443
  PDF Jul-71

Dumortierite Image

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Comments: Blue dumortierite in matrix.
Location: Hartmannsdorf, Chemnitz, Saxony, Germany. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

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Comments: Divergent fans of acicular purple to lilac colored dumortierite crystals in white andalusite matrix.
Location: Dehesa, San Diego Co., California, USA. Scale: Crystal size 2.3cm.
© Tom Loomis / Dakota Matrix

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Comments: Low-magnification, bright-field image showing dispersed dumortierite fibers extracted from rose quartz on a carbon film. (AmMin 87:270).
Location: Madagascar. Scale: See Image.
© American Mineralogist

Dumortierite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5827:1:0.2338
Help on Cell Dimensions: Cell Dimensions: a = 11.76, b = 20.18, c = 4.72, Z = 4; V = 1,120.14 Den(Calc)= 3.38
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcmn
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.549(1), 5.09(0.9), 5.89(0.9),
Help on Forms: Forms:

Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu

Help on Above

Forms: ( 1 0 0) ( 0 0 1) ( 1 1 0) ( 1 3 0) ( 0 1 0)

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Physical Properties of Dumortierite

Help on Cleavage: Cleavage: {100} Good, {110} Indistinct
Help on Color: Color: Blue, Brown, Violet, Greenish blue, Pink.
Help on Density: Density: 3.3 - 3.4, Average = 3.34
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Fibrous - Thin, elongated fractures produced by crystal forms or intersecting cleavages (e.g. asbestos).
Help on Habit: Habit: Columnar - Forms columns
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 8.5 - Chrysoberyl
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: white

Optical Properties of Dumortierite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.028 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.037 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2017,KPDmeas= 0.2035,KC= 0.2094
Ncalc = 1.69 - 1.71
Help on Optical Data: Optical Data: Biaxial (-), a=1.659-1.678, b=1.684-1.691, g=1.686-1.692, bire=0.0140-0.0270, 2V(Calc)=30, 2V(Meas)=20-52. Dispersion r > v or r < v.
Help on Pleochroism (x): Pleochroism (x): blue, violet, greenish blue, or deep rose.
Help on Pleochroism (y): Pleochroism (y): colorless, reddish violet, pale lilac blue, or yellow.

Calculated Properties of Dumortierite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.31 gm/cc
note: Specific Gravity of Dumortierite =3.35 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEDumortierite = 1.55 barns/electron
U=PEDumortierite x rElectron Density= 5.11 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Dumortierite is Not Radioactive

Dumortierite Classification

Help on  Dana Class: Dana Class: (54)Nesosilicate Borosilicates and Some Beryllosilicates
  (54.01)with (BO3)
  (54.01.02)Dumortierite group Dumortierite Al6.5-7(BO3)(SiO4)3(O,OH)3 Pcmn 2/m 2/m 2/m Magnesiodumortierite (Mg,Ti,[])<1(Al,Mg)2Al4Si3O18-y(OH)yBy=2-3 Pmcn 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.AJ.10 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AJ -Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra,
09.AJ.10 Dumortierite Al6.5-7(BO3)(SiO4)3(O,OH)3 Pcmn 2/m 2/m 2/m
09.AJ.10 Holtite Al6(Al,Ta)(BO3)[(SiO4,SbO4,AsO4)]3(O,OH)3 P nma 2/m 2/m 2/m
09.AJ.10 Magnesiodumortierite (Mg,Ti,[])<1(Al,Mg)2Al4Si3O18-y(OH)yBy=2-3 Pmcn 2/m 2/m 2/m

Other Dumortierite Information

Help on See Also: See Also: Links to other databases for Dumortierite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - CalTech Mineral Spectroscopy
5 - Diederik Visser
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - Scandinavian mineral gallery

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Dana No: Strunz No: 09.AJ.10





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