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Ettringite Mineral Data

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General Ettringite Information

Help on Chemical  Formula: Chemical Formula: Ca6Al2(SO4)3(OH)12•26(H2O)
Help on Composition: Composition: Molecular Weight = 1,255.11 gm
   Calcium   19.16 %  Ca   26.81 % CaO
   Aluminum   4.30 %  Al    8.12 % Al2O3
   Hydrogen   5.14 %  H    45.93 % H2O
   Sulfur     7.66 %  S    19.14 % SO3
   Oxygen    63.74 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca6Al2(SO4)3(OH)12•26(H2O)
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1874
Help on Locality: Locality: Ettringer Bellerberg, Ettringen, Mayen, Eifel, Rheinland-Pfalz, Germany Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality
Help on Name Pronunciation: Name Pronunciation: Ettringite + Pronunciation Say ETTRINGITE
Help on Synonym: Synonym: ICSD 16045
  PDF 41-1451
 

Ettringite Image

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  Ettringite

Comments: Small glassy whitish micro crystals of ettringite on a white powdery matrix.
Location: Ettringen, Eifel, Allemagne, Germany. Scale: 2.5 x 1 x 2 cm.
© John Veevaert

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  Ettringite

Comments: Doubly-terminated crystals of glassy yellow ettringite on matrix.
Location: N'Chwaning Mine, near Kuruman, South Africa. Scale: Crystal size 4 cm.
© Rob Lavinsky

Ettringite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.95458
Help on Cell Dimensions: Cell Dimensions: a = 22.46, c = 21.44, Z = 8; V = 9,366.45 Den(Calc)= 1.78
Help on Crystal System: Crystal System: Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 63/mmc
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 9.65(1), 5.58(0.8), 3.21(0.6),
 

Physical Properties of Ettringite

Help on Cleavage: Cleavage: {1010} Perfect
Help on Color: Color: Colorless, White.
Help on Density: Density: 1.8
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Hardness: Hardness: 2-2.5 - Gypsum-Finger Nail
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 Ettringite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.014 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.026 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2699,KPDmeas= 0.2669,KC= 0.2632
Ncalc = 1.47
Help on Optical Data: Optical Data: Uniaxial (-), e=1.47, w=1.491, bire=0.0210.
 

Calculated Properties of Ettringite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=1.89 gm/cc
note: Specific Gravity of Ettringite =1.80 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0011471359
Boson Index = 0.9988528641
Help on Photoelectric: Photoelectric: PEEttringite = 2.97 barns/electron
U=PEEttringite x rElectron Density= 5.60 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Ettringite is Not Radioactive
 

Ettringite Classification

Help on  Dana Class: Dana Class: 31.10.02.01 (31)Hydrated Sulfates Containing Hydroxyl or Halogen
  (31.10)miscellaneous
  (31.10.02)Dana Group
 
31.10.02.01 Ettringite Ca6Al2(SO4)3(OH)12•26(H2O) P 63/mmc 6/m 2/m 2/m
 
31.10.02.02 Bentorite Ca6(Cr,Al)2(SO4)3(OH)12•26(H2O) P 63/mmc 6/m 2/m 2/m
 
31.10.02.03 Buryatite! Ca3(Si,Fe,Al)[SO4][B(OH)4](OH,O)6•12(H2O) P 31c 3m
Help on  Strunz Class: Strunz Class: 07.DG.15 07 - SULFATES (SELENATES, TELLURATES)
  07.D - Sulfates (selenates, etc.) with additional anions, with H2O
  07.DG -With large and medium sized cations; with NO3, CO3, B(OH)4, SiO4 or IO3
 
07.DG.15 Bentorite Ca6(Cr,Al)2(SO4)3(OH)12•26(H2O) P 63/mmc 6/m 2/m 2/m
 
07.DG.15 Charlesite Ca6(Al,Si)2(SO4)2B(OH)4(OH,O)12•26(H2O) P 31c 3m
 
07.DG.15 Ettringite Ca6Al2(SO4)3(OH)12•26(H2O) P 63/mmc 6/m 2/m 2/m
 
07.DG.15 Jouravskite Ca3Mn(SO4,CO3)2(OH)6•12(H2O) P 63/m 6/m
 
07.DG.15 Sturmanite Ca6(Fe,Al,Mn)2(SO4)2[B(OH)4](OH)12•25(H2O) P 31c 3m
 
07.DG.15 Thaumasite Ca3Si(CO3)(SO4)(OH)6•12(H2O) P 63/m 6/m
 
07.DG.15 Buryatite! Ca3(Si,Fe,Al)[SO4][B(OH)4](OH,O)6•12(H2O) P 31c 3m
 
07.DG.15 Carraraite! Ca3Ge(OH)6(SO4)(CO3)•12H2O P 63/m, or P 63 Hex
 

Other Ettringite Information

Help on References: References: PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Ettringite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST
17 - theimage

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

Ettringite

Ca6Al2(SO4)3(OH)12•26(H2O)
Dana No: 31.10.02.01 Strunz No: 07.DG.15
Locality:

 

Notes:

 

 
   
 


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