Mineralogy Database

Sepiolite Mineral Data

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General Sepiolite Information

Help on Chemical  Formula: Chemical Formula: Mg4Si6O15(OH)2•6(H2O)
Help on Composition: Composition: Molecular Weight = 613.82 gm
   Magnesium  15.84 %  Mg   26.26 % MgO
   Silicon    27.45 %  Si   58.73 % SiO2
   Hydrogen    1.97 %  H    17.61 % H2O
   Oxygen     54.74 %  O
             ______        ______ 
             100.00 %      102.61 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg4Si6O15•6(H2O)
Help on Environment: Environment: Secondary mineral associated with serpentine. Can precipitate from alkali saline waters in arid environments.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1847
Help on Locality: Locality: Eski Shehr, Asia Minor. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek, sepia - "cuttlefish" and lithos - "stone." From the German, meerschaum meaning "sea froth."
Help on Name Pronunciation: Name Pronunciation: Sepiolite + Pronunciation Say SEPIOLITE
Help on Synonym: Synonym: ICSD 31142
  PDF 26-1226
  Sea Foam

Sepiolite Image

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Comments: Sectile to chalky massive sepiolite.
Location: Pinos Altos, Grant County, New Mexico. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Sepiolite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.4996:1:0.1964
Help on Cell Dimensions: Cell Dimensions: a = 13.43, b = 26.88, c = 5.281, Z = 4; V = 1,906.43 Den(Calc)= 2.14
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnan
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 12.3(1), 2.58(0.6), 4.4(0.35),

Physical Properties of Sepiolite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Grayish white, Yellowish white, Bluish green white, Reddish white, Gray.
Help on Density: Density: 2
Help on Diaphaneity: Diaphaneity: Opaque
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Hardness: Hardness: 2 - Gypsum
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Earthy (Dull)
Help on Streak: Streak: white

Optical Properties of Sepiolite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.116 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.043 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2446,KPDmeas= 0.2617,KC= 0.2346
Ncalc = 1.47 - 1.5
Help on Optical Data: Optical Data: Biaxial (-), a=1.52, b=1.5202, g=1.53, bire=0.0100, 2V(Calc)=18, 2V(Meas)=20-70. Dispersion none.

Calculated Properties of Sepiolite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.18 gm/cc
note: Specific Gravity of Sepiolite =2.14 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PESepiolite = 1.43 barns/electron
U=PESepiolite x rElectron Density= 3.12 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Sepiolite is Not Radioactive

Sepiolite Classification

Help on  Dana Class: Dana Class: 74.03.01b.01 (74)Phyllosilicate Modulated Layers
  (74.03)with joined strips
  (74.03.01b)Palygorskite-sepiolite group (Sepiolite subgroup)
74.03.01b.01 Sepiolite Mg4Si6O15(OH)2•6(H2O) Pnan 2/m 2/m 2/m
74.03.01b.02 Falcondoite (Ni,Mg)4Si6O15(OH)2•6(H2O) Pncn 2/m 2/m 2/m
74.03.01b.03 Loughlinite Na2Mg3Si6O16•8(H2O) Unk Ortho
Help on  Strunz Class: Strunz Class: 09.EE.25 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EE -Single tetrahedral nets of 6-membered rings
09.EE.25 Falcondoite (Ni,Mg)4Si6O15(OH)2•6(H2O) Pncn 2/m 2/m 2/m
09.EE.25 Loughlinite Na2Mg3Si6O16•8(H2O) Unk Ortho
09.EE.25 Kalifersite! (K,Na)5Fe7Si20O50(OH)6•12(H2O) P1 1
09.EE.25 Sepiolite Mg4Si6O15(OH)2•6(H2O) Pnan 2/m 2/m 2/m

Other Sepiolite Information

Help on References: References: NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Sepiolite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - Franklin Minerals(Dunn)
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - YupRocks

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Dana No: 74.03.01b.01 Strunz No: 09.EE.25





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