Bentorite Mineral Data

Advertisment

McDougall Minerals sells high-quality mineral specimens from all over the world to collectors of all levels, from beginners to connoisseurs

John Betts - Fine Minerals, New York. Dealers of Fine Minerals and Natural Crystal Clusters since 1989. We buy rock collections, we buy gem collections, we buy mineral collections.

Weinrich Minerals, A Dealer in Fine Mineral Specimens - Since 1989. We buy collections and single high quality specimens.

General Bentorite Information

Chemical Formula:

Ca6(Cr,Al)2(SO4)3(OH)12•26(H2O)

Composition:

Molecular Weight = 1,292.63 gm

Calcium 18.60 % Ca 26.03 % CaO

Aluminum 1.04 % Al 1.97 % Al₂O₃

Chromium 6.03 % Cr 8.82 % Cr₂O₃

Hydrogen 4.99 % H 44.60 % H₂O

Sulfur 7.44 % S 18.58 % SO₃

Oxygen 61.89 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₆Cr_1.5Al_0.5(SO₄)₃(OH)₁₂•26(H₂O)

Environment:

Low-temperature hydrothermal veins in black calcite–spurrite marble.

IMA Status:

Approved IMA 1980

Locality:

Marble quarry in the Hatrurim Formation, near the Arad-Sodom road, Negev Desert, Israel. Link to MinDat.org Location Data.

Name Origin:

Named for Y.K. Bentor, Professor at the University of California, San Diego, California, USA, for his contributions to geology and mineralogy in Israel.

Name Pronunciation:

Bentorite + Pronunciation

Bentorite Image

Images:

Bentorite

Comments: Violet crystalline bentorite.
Location: Hatrurim Area, West of Dead Sea, Israel. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bentorite Crystallography

Axial Ratios:

a:c = 1:0.95794

Cell Dimensions:

a = 22.35, c = 21.41, Z = 8; V = 9,261.95 Den(Calc)= 1.85

Crystal System:

Hexagonal - Dihexagonal DipyramidalH-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 9.656(1), 5.592(0.4), 1.942(0.2),

Physical Properties of Bentorite

Cleavage:

{1010} Perfect

Color:

Violet, Light violet.

Density:

2.025

Diaphaneity:

Transparent

Hardness:

2 - Gypsum

Luster:

Vitreous (Glassy)

Streak:

violet

Optical Properties of Bentorite

Gladstone-Dale:

CI meas= 0.116 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.033 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.26,KPDmeas= 0.2375,KC= 0.2688
Ncalc = 1.5 - 1.54

Optical Data:

Uniaxial (+), w=1.478, e=1.484, bire=0.0060.

Calculated Properties of Bentorite

Electron Density:

Bulk Density (Electron Density)=1.93 gm/cc
note: Specific Gravity of Bentorite =1.85 gm/cc.

Fermion Index:

Fermion Index = 0.0068459104
Boson Index = 0.9931540896

Photoelectric:

PE_Bentorite= 4.06 barns/electron
U=PE_Bentorite x rElectron Density= 7.84 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Bentorite is Not Radioactive

Bentorite Classification

Dana Class:

31.10.02.02 (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

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 Bentorite Information

References:

NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Bentorite :
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

Search for Bentorite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Bentorite :

A Bijoux Google Search for Bentorite
Adam's Minerals Google Search for Bentorite
Cape Minerals Google Search for Bentorite
Dakota Matrix Minerals Google Search for Bentorite
Excalibur Mineral Corp. Google Search for Bentorite
Exceptional Minerals Google Search for Bentorite
John Betts Fine Minerals Search for Bentorite
McDougall Minerals Google Search for Bentorite
Mineral News Website Link
Rock and Mineral Shows Google Search for Bentorite
Weinrich Minerals, Inc. Google Search for Bentorite

Ask about Bentorite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Bentorite

Ca6(Cr,Al)2(SO4)3(OH)12•26(H2O)
Dana No: 31.10.02.02 Strunz No: 07.DG.15
Locality:

Notes: