Mineralogy Database

Cordierite Mineral Data

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General Cordierite Information

Help on Chemical  Formula: Chemical Formula: Mg2Al4Si5O18
Help on Composition: Composition: Molecular Weight = 584.95 gm
   Magnesium   8.31 %  Mg   13.78 % MgO
   Aluminum   18.45 %  Al   34.86 % Al2O3
   Silicon    24.01 %  Si   51.36 % SiO2
   Oxygen     49.23 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg2Al4Si5O18
Help on Environment: Environment: Magmatic, metamorphic, and pegmatitic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1813
Help on Locality: Locality: Bodenmais, Germany. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the French mining engineer and geologist P. L. A. Cordier (1777-1861).
Help on Name Pronunciation: Name Pronunciation: Cordierite + Pronunciation Say CORDIERITE
Help on Synonym: Synonym: Dichroite
  ICSD 100250
  PDF 12-303

Cordierite Image

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Comments: Brown rectangular cordierite crystals in matrix. These crystals are not gemmy enough to be called iolite.
Location: Richmond Soapstone Quarry, Richmond, Cheshire Co., New Hampshire, USA. Scale: 24x20x15 mm.
© John Betts - Fine Minerals

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Comments: Piece of near-gem-quality glassy gray-blue cordierite with some yellowish internal reflections.
Location: Mt. Bity District, Madagascar. Scale: Overall: 2 x 1 x 1.5 cm.
© Tom Loomis / Dakota Matrix

Cordierite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.7479:1:0.954
Help on Cell Dimensions: Cell Dimensions: a = 17.13, b = 9.8, c = 9.35, Z = 4; V = 1,569.62 Den(Calc)= 2.48
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: C ccm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.13(1), 8.45(0.8), 8.54(0.8),

Physical Properties of Cordierite

Help on Cleavage: Cleavage: {010} Poor
Help on Color: Color: Colorless, Pale blue, Violet, Yellow, Gray.
Help on Density: Density: 2.55 - 2.75, Average = 2.65
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 7 - Quartz
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Cordierite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.077 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2224,KPDmeas= 0.2081,KC= 0.2065
Ncalc = 1.51 - 1.57
Help on Optical Data: Optical Data: Biaxial (-), a=1.527-1.56, b=1.532-1.574, g=1.538-1.578, bire=0.0110-0.0180, 2V(Calc)=54-86, 2V(Meas)=75-89. Dispersion weak, r < v.
Help on Pleochroism (x): Pleochroism (x): colorless, pale yellow, or pale yellow.
Help on Pleochroism (y): Pleochroism (y): colorless, violet, or blue.

Calculated Properties of Cordierite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.63 gm/cc
note: Specific Gravity of Cordierite =2.65 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PECordierite = 1.65 barns/electron
U=PECordierite x rElectron Density= 4.32 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Cordierite is Not Radioactive

Cordierite Classification

Help on  Dana Class: Dana Class: (61)Cyclosilicate Six-Membered Rings
  (61.02)with Al substituted rings
  (61.02.01)Cordierite group Cordierite Mg2Al4Si5O18 C ccm 2/m 2/m 2/m Sekaninaite (Fe,Mg)2Al4Si5O18 C ccm 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.CJ.10 09 - SILICATES (Germanates)
  09.C - Cyclosilicates
  09.CJ -[Si6O18]12- 6-membered single rings (sechser-Einfachringe),
09.CJ.10 Cordierite Mg2Al4Si5O18 C ccm 2/m 2/m 2/m
09.CJ.10 Sekaninaite (Fe,Mg)2Al4Si5O18 C ccm 2/m 2/m 2/m

Other Cordierite Information

Help on See Also: See Also: Links to other databases for Cordierite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - CalTech Mineral Spectroscopy
7 - EUROmin Project
8 - Ecole des Mines de Paris
9 - GeoScienceWorld
10 - Google Images
11 - Google Scholar
12 - Handbook of Mineralogy (MinSocAm)
13 - Handbook of Mineralogy (UofA)
14 - MinDAT
15 - Mineralienatlas (Deutsch)
16 - Online Mineral Museum
17 - Philatelic Mineralogy
18 - QUT Mineral Atlas
19 - Ruff.Info
20 - Scandinavian mineral gallery
21 - Tradeshop.com - The Rainbow of Gems
22 - UCLA - Petrography Thin-Sections

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Dana No: Strunz No: 09.CJ.10





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