Mineralogy Database

Benstonite Mineral Data

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General Benstonite Information

Help on Chemical  Formula: Chemical Formula: (Ba,Sr)6(Ca,Mn)6Mg(CO3)13
Help on Composition: Composition: Molecular Weight = 1,816.58 gm
   Barium     34.02 %  Ba   37.98 % BaO
   Strontium   7.24 %  Sr    8.56 % SrO
   Calcium     9.93 %  Ca   13.89 % CaO
   Magnesium   1.34 %  Mg    2.22 % MgO
   Manganese   4.54 %  Mn    5.86 % MnO
   Carbon      8.60 %  C    31.49 % CO2
   Oxygen     34.35 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ba4.5Sr1.5Ca4.5Mn2+1.5Mg(CO3)13
Help on Environment: Environment: Barite deposit.
Help on IMA Status: IMA Status: Approved IMA 1961
Help on Locality: Locality: Magnet Cove, Arkansas, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Orlando J. Benston (1901-1966), metallurgist for the Baroid Division, National Lead Co., Malvern, Arkansas, USA, who supplied the first specimens.
Help on Name Pronunciation: Name Pronunciation: Benstonite + Pronunciation Say BENSTONITE
Help on Synonym: Synonym: ICSD 100479
  PDF 14-637

Benstonite Image

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Comments: Light pink benstonite crystals epitaxially formed on calcite needles.
Location: Minerva #1 Mine, Hardin County, Illinois, USA. Scale: 13 x 11 mm.
© John Veevaert

Benstonite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.47428
Help on Cell Dimensions: Cell Dimensions: a = 18.28, c = 8.67, Z = 3; V = 2,509.01 Den(Calc)= 3.61
Help on Crystal System: Crystal System: Trigonal - Pyramidal H-M Symbol (3) Space Group: R 3
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.08(1), 3.92(0.4), 2.536(0.3),

Physical Properties of Benstonite

Help on Cleavage: Cleavage: {???} Good
Help on Color: Color: Snow white, Yellow brown, White, Light yellow.
Help on Density: Density: 3.596 - 3.66, Average = 3.62
Help on Diaphaneity: Diaphaneity: Translucent
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luminescence: Luminescence: Fluorescent and phosphorescent, Short UV=yellow to red, Long UV=yellow to red.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Benstonite

Help on Dichroism (e): Dichroism (e): colorless.
Help on Dichroism (w): Dichroism (w): colorless.
Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.028 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1686,KPDmeas= 0.1677,KC= 0.1726
Ncalc = 1.62 - 1.63
Help on Optical Data: Optical Data: Uniaxial (-), e=1.527, w=1.69, bire=0.1630.

Calculated Properties of Benstonite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.33 gm/cc
note: Specific Gravity of Benstonite =3.61 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.06
Boson Index = 0.94
Help on Photoelectric: Photoelectric: PEBenstonite = 158.66 barns/electron
U=PEBenstonite x rElectron Density= 528.74 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Benstonite is Not Radioactive

Benstonite Classification

Help on  Dana Class: Dana Class: (14)Anhydrous Carbonates
  (14.02)with Compound Formula A+ B++ (CO3)2
  (14.02.03)Dana Group Benstonite (Ba,Sr)6(Ca,Mn)6Mg(CO3)13 R 3 3
Help on  Strunz Class: Strunz Class: 05.AB.55 05 - CARBONATES (NITRATES)
  05.A - Carbonates without additional anions, without H2O
  05.AB -Alkali-earth (and other M2+) carbonates
05.AB.55 Benstonite (Ba,Sr)6(Ca,Mn)6Mg(CO3)13 R 3 3

Other Benstonite Information

Help on References: References: NAME( AntBidBlaNic3) 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 Benstonite :
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

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Dana No: Strunz No: 05.AB.55





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