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Andalusite Mineral Data

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General Andalusite Information

Help on Chemical  Formula: Chemical Formula: Al2SiO5 = Al[6]Al[5]OSiO4
Help on Composition: Composition: Molecular Weight = 162.05 gm
   Aluminum  33.30 %  Al   62.92 % Al2O3
   Silicon   17.33 %  Si   37.08 % SiO2
   Oxygen    49.37 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Al2SiO5
Help on Environment: Environment: Metamorphosed peri-aluminous sedimentary rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1789
Help on Locality: Locality: Andalucia (Spain), an early but now unimportant location. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its locality.
Help on Name Pronunciation: Name Pronunciation: Andalusite + Pronunciation Say ANDALUSITE
Help on Synonym: Synonym: Chiastolite
  ICSD 24275
  PDF 39-376

Andalusite Image

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Comments: Wine colored andalusite associated with mica.
Location: Sierra Albarrana, Cordoba, Spain. Scale: 4.5 x 3.5 cm.
© Fabre Minerals

Andalusite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.986:1:0.7037
Help on Cell Dimensions: Cell Dimensions: a = 7.79, b = 7.9, c = 5.56, Z = 4; V = 342.17 Den(Calc)= 3.15
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnnm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 5.54(1), 2.77(0.9), 4.53(0.9),

Physical Properties of Andalusite

Help on Cleavage: Cleavage: {110} Distinct, {100} Indistinct, {010} Poor
Help on Color: Color: Dark green, Gray, Brown, Red, Green.
Help on Density: Density: 3.13 - 3.17, Average = 3.15
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Splintery - Thin, elongated fractures produced by intersecting good cleavages or partings (e.g. hornblende).
Help on Habit: Habit: Blocky - Crystal shape tends to be equant (e.g. feldspars).
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 6.5-7 - Pyrite-Quartz
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Andalusite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.022 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.022 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2029,KPDmeas= 0.2029,KC= 0.2074
Ncalc = 1.65 - 1.66
Help on Optical Data: Optical Data: Biaxial (-), a=1.629-1.64, b=1.633-1.644, g=1.638-1.65, bire=0.0090-0.0100, 2V(Calc)=80-84, 2V(Meas)=48-68. Dispersion r > v.
Help on Pleochroism (x): Pleochroism (x): pink, light red, or yellow.
Help on Pleochroism (y): Pleochroism (y): colorless, pale yellow, or green.

Calculated Properties of Andalusite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.11 gm/cc
note: Specific Gravity of Andalusite =3.15 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0083309363
Boson Index = 0.9916690637
Help on Photoelectric: Photoelectric: PEAndalusite = 1.64 barns/electron
U=PEAndalusite x rElectron Density= 5.10 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Andalusite is Not Radioactive

Andalusite Classification

Help on  Dana Class: Dana Class: 52.02.02b.01 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O
  (52.02)with cations in [4] and >[4] coordination
  (52.02.02b)AL2SIO5 Andalusite subgroup)
52.02.02b.01 Andalusite Al2SiO5=Al[6]Al[5]OSiO4 Pnnm 2/m 2/m 2/m
52.02.02b.02 Kanonaite (Mn,Al)AlSiO5 Pnnm 2/m 2/m 2/m
52.02.02b.03 Yoderite Mg2(Al,Fe)6Si4O18(OH)2 P 21 2
Help on  Strunz Class: Strunz Class: 09.AF.10 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AF -Nesosilicates with additional anions;
09.AF.10 Andalusite Al2SiO5=Al[6]Al[5]OSiO4 Pnnm 2/m 2/m 2/m
09.AF.10 Kanonaite (Mn,Al)AlSiO5 Pnnm 2/m 2/m 2/m

Other Andalusite Information

Help on See Also: See Also: Links to other databases for Andalusite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - CalTech Mineral Spectroscopy
5 - GeoScienceWorld
6 - Glendale Community College
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - HyperPhysics
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Minerals in Thin Section-University of North Carolina
15 - Minerals in Thin Sections-Humboldt State
16 - Online Mineral Museum
17 - QUT Mineral Atlas
18 - Ruff.Info
19 - Scandinavian mineral gallery
20 - Tradeshop.com - The Rainbow of Gems
21 - UCLA - Petrography Thin-Sections
22 - University of Colorado - Mineral Structure Data
24 - theimage

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Ask about Andalusite here :
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Print or Cut-and-Paste your Andalusite Specimen Label here :


Al2SiO5 = Al[6]Al[5]OSiO4
Dana No: 52.02.02b.01 Strunz No: 09.AF.10





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