Okenite Mineral Data

General Okenite Information

Chemical Formula:

Ca3[Si6O15]•6(H2O)

Composition:

Molecular Weight = 1,966.57 gm

Calcium 20.38 % Ca 28.52 % CaO

Silicon 25.71 % Si 55.00 % SiO₂

Hydrogen 1.85 % H 16.49 % H₂O

Oxygen 52.07 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₁₀Si₁₈O₄₆•18(H₂O)

Environment:

Secondary mineral from the alteration of basalts.

IMA Status:

Valid Species (Pre-IMA) 1828

Locality:

Disko Island, Greenland. Poona, near Bombay, India. Link to MinDat.org Location Data.

Name Origin:

Named for Lorenz Oken (1779-1851), German natural historian, Munich Germany.

Name Pronunciation:

Okenite

Synonym:

ICSD 31207

PDF 33-305

Okenite Image

Images:

Okenite

Comments: Cotton-ball cluster of white okenite crystals.
Location: Khandivali quarry, Maharashtra, India. Scale: 3x3x2 cm.
© John Betts - Fine Minerals

Okenite Crystallography

Axial Ratios:

a:b:c =1.331:1:3.0219

Cell Dimensions:

a = 9.69, b = 7.28, c = 22, Z = 1; alpha = 97.5°, beta = 101.1°, gamma = 110.9° V = 1,410.54 Den(Calc)= 2.31

Crystal System:

Triclinic Space Group: P1 or P1

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

By Intensity(I/I_o): 21(1), 3.56(0.8), 8.8(0.8),

Physical Properties of Okenite

Cleavage:

{001} Good

Color:

White, Yellowish white, Bluish white.

Density:

2.3 - 2.33, Average = 2.31

Diaphaneity:

Transparent to Translucent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Capillary - Very slender and long, like a thread or hair (e.g. millerite).

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Spherical - Spherical, rounded aggregates.

Hardness:

5 - Apatite

Luminescence:

Non-Fluorescent.

Luster:

Pearly

Streak:

white

Optical Properties of Okenite

Gladstone-Dale:

CI meas= 0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2234,KPDmeas= 0.2268,KC= 0.2303
Ncalc = 1.53 - 1.54

Optical Data:

Biaxial (-), a=1.512-1.532, b=1.514-1.535, g=1.515-1.542, bire=0.0030-0.0100, 2V(Calc)=68-70, 2V(Meas)=60. Dispersion none.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Okenite

Electron Density:

Bulk Density (Electron Density)=2.35 gm/cc
note: Specific Gravity of Okenite =2.32 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Okenite= 3.48 barns/electron
U=PE_Okenite x rElectron Density= 8.20 barns/cc.

Radioactivity:

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

Okenite Classification

Dana Class:

72.03.02.05 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings

(72.03)with 3-, 4-, or 5-membered rings and 8-membered rings

(72.03.02)Tobermorite group (5- & 8-membered rings)

72.03.02.01 Tobermorite Ca5Si6O16(OH)2•4(H2O) C 222₁ 2 2 2

72.03.02.02 Clinotobermorite Ca5Si6(O,OH)18•5(H2O) Cc,C 2/c Mono

72.03.02.03 Plombierite Ca5H2Si6O18•6H2O B11b 2

72.03.02.04 Riversideite Ca5Si6O16(OH)2•2(H2O) B2212 2 2 2

72.03.02.05 Okenite Ca3[Si6O15]•6(H2O) P1 or P1 Tri

72.03.02.06 Tacharanite Ca12Al2Si18O33(OH)36 A centered Mono

72.03.02.07 Nekoite Ca3Si6O15•7(H2O) P1 1

72.03.02.08 Oyelite Ca10B2Si8O29•12(H2O) B**** Ortho

Strunz Class:

09.EA.40 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EA -Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings

09.EA.40 Okenite Ca3[Si6O15]•6(H2O) P1 or P1 Tri

Other Okenite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Okenite :
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 - Glendale Community College
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST
18 - theimage

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Okenite

Ca3[Si6O15]•6(H2O)
Dana No: 72.03.02.05 Strunz No: 09.EA.40
Locality:

Notes:

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