General Benstonite Information Chemical Formula: |
(Ba,Sr)6(Ca,Mn)6Mg(CO3)13 |
Composition: |
Molecular Weight = 1,816.58 gm |
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Barium 34.02 % Ba 37.98 % BaO |
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Strontium 7.24 % Sr 8.56 % SrO |
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Calcium 9.93 % Ca 13.89 % CaO |
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Magnesium 1.34 % Mg 2.22 % MgO |
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Manganese 4.54 % Mn 5.86 % MnO |
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Carbon 8.60 % C 31.49 % CO2 |
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Oxygen 34.35 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Ba4.5Sr1.5Ca4.5Mn2+1.5Mg(CO3)13 |
Environment: |
Barite deposit. |
IMA Status: |
Approved IMA 1961 |
Locality: |
Magnet Cove, Arkansas, USA. Link to MinDat.org Location Data. |
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. |
Name Pronunciation: |
Benstonite + Pronunciation |
Synonym: |
ICSD 100479 |
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PDF 14-637 |
| | Benstonite Image
Images:
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Benstonite Crystallography Axial Ratios: |
a:c = 1:0.47428 |
Cell Dimensions: |
a = 18.28, c = 8.67, Z = 3; V = 2,509.01 Den(Calc)= 3.61 |
Crystal System: |
Trigonal - PyramidalH-M Symbol (3) Space Group: R 3 |
X Ray Diffraction: |
By Intensity(I/Io): 3.08(1), 3.92(0.4), 2.536(0.3), |
Crystal Structure:
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Mouse
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| Physical Properties of Benstonite Cleavage: |
{???} Good |
Color: |
Snow white, Yellow brown, White, Light yellow. |
Density: |
3.596 - 3.66, Average = 3.62 |
Diaphaneity: |
Translucent |
Hardness: |
3-4 - Calcite-Fluorite |
Luminescence: |
Fluorescent and phosphorescent, Short UV=yellow to red, Long UV=yellow to red. |
Luster: |
Vitreous (Glassy) |
Streak: |
white |
| Optical Properties of Benstonite Dichroism (e): |
colorless. |
Dichroism (w): |
colorless. |
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 Optical Data: |
Uniaxial (-), e=1.527, w=1.69, bire=0.1630. |
| Calculated Properties of Benstonite Electron Density: |
Bulk Density (Electron Density)=3.33 gm/cc |
note: Specific Gravity of Benstonite =3.61 gm/cc. Fermion Index: |
Fermion Index = 0.06 |
Boson Index = 0.94 Photoelectric: |
PEBenstonite = 158.66 barns/electron |
U=PEBenstonite x rElectron Density= 528.74 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Benstonite is Not Radioactive | Benstonite Classification Dana Class: |
14.02.03.01 (14)Anhydrous Carbonates |
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(14.02)with Compound Formula A+ B++ (CO3)2 |
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(14.02.03)Dana Group |
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Strunz Class: |
05.AB.55 05 - CARBONATES (NITRATES) |
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05.A - Carbonates without additional anions, without H2O |
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05.AB -Alkali-earth (and other M2+) carbonates |
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| Other Benstonite Information References: |
NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990) |
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 15 - WWW-MINCRYST Search for Benstonite using: Visit our Advertisers for Benstonite : A Bijoux Google Search for BenstoniteAdam's Minerals Google Search for Benstonite Cape Minerals Google Search for Benstonite Dakota Matrix Minerals Google Search for Benstonite Excalibur Mineral Corp. Google Search for Benstonite Exceptional Minerals Google Search for Benstonite John Betts Fine Minerals Search for Benstonite McDougall Minerals Google Search for Benstonite Mineral News Website Link Rock and Mineral Shows Google Search for Benstonite Weinrich Minerals, Inc. Google Search for Benstonite Ask about Benstonite here : Print or Cut-and-Paste your Benstonite Specimen Label here :
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