Stilbite-Na Mineral Data

General Stilbite-Na Information

Chemical Formula:

Na3Ca3[Al8Si28O72]•n(H2O) (n=28-32)

Composition:

Molecular Weight = 2,883.86 gm

Sodium 2.39 % Na 3.22 % Na₂O

Calcium 4.17 % Ca 5.83 % CaO

Aluminum 7.48 % Al 14.14 % Al₂O₃

Silicon 27.27 % Si 58.34 % SiO₂

Hydrogen 2.10 % H 18.74 % H₂O

Oxygen 56.59 % O

______ ______

100.00 % 100.28 % = TOTAL OXIDE

Empirical Formula:

Na₃Ca₃Al₈Si₂₈O₇₂•30(H₂O)

Environment:

Amygdaloidal cavities in basalts and similar rocks.

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

Capo Pula, Cagliari, Sardinia, Italy. Link to MinDat.org Location Data.

Name Origin:

From the Greek stilbe - "luster" in allusion to the pearly to vitreous luster. The Na-dominant member of the stilbite series.

Name Pronunciation:

Stilbite-Na

Synonym:

Aedelforsite

Bundle zeolite

Desmine

Epidesmine

Stilbite-Na Image

Images:

Stilbite-Na

Comments: Stibite 'bow-ties' on matrix.
Location: Cape Pula, Pula, Cagliari Province, Sardinia, Italy. Scale: Largest Crystal Length 3 cm.
© Ed Rosenzweig

Stilbite-Na Crystallography

Axial Ratios:

a:b:c =0.7501:1:0.6224

Cell Dimensions:

a = 13.63, b = 18.17, c = 11.31, Z = 1; beta = 129.166° V = 2,171.67 Den(Calc)= 2.20

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 9.04(1), 4.07(0.95), 3.04(0.7),

Physical Properties of Stilbite-Na

Cleavage:

{010} Perfect

Color:

White, Red, Yellow, Brown, Cream.

Density:

2.1 - 2.2, Average = 2.15

Diaphaneity:

Transparent to Subtransparent to translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Globular - Spherical, or nearly so, rounded forms (e.g. wavellite).

Habit:

Wheat Sheaf - Bundle shaped aggregates resembling wheat sheafs after hand reaping wheat.

Hardness:

3.5-4 - Copper Penny-Fluorite

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Stilbite-Na

Gladstone-Dale:

CI meas= 0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.04 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2235,KPDmeas= 0.2287,KC= 0.2327
Ncalc = 1.49 - 1.51

Optical Data:

Biaxial (-), a=1.479-1.492, b=1.485-1.5, g=1.489-1.505, bire=0.0100-0.0130, 2V(Calc)=76-78, 2V(Meas)=22-79. Dispersion weak, r < v.

Calculated Properties of Stilbite-Na

Electron Density:

Bulk Density (Electron Density)=2.18 gm/cc
note: Specific Gravity of Stilbite-Na =2.15 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Stilbite-Na= 1.85 barns/electron
U=PE_Stilbite-Na x rElectron Density= 4.04 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Stilbite-Na is Not Radioactive

Stilbite-Na Classification

Dana Class:

77.01.04.03a (77)Tectosilicate Zeolite group

(77.01)true zeolites

(77.01.04)Heulandite and related species

77.01.04.01 Heulandite-Ca (Ca,Na)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, Cm, C 2 Mono

77.01.04.01a Heulandite-Na! (Na,Ca)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, Cm, C 2 Mono

77.01.04.01b Heulandite-K! (K,Na,Ca)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, Cm, C 2 2/m

77.01.04.01c Heulandite-Sr! (Sr,Na,Ca)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, Cm, C 2 Mono

77.01.04.01d Heulandite-Ba! (Ba,Ca,K,Na,Sr)5Al9Si27O72•22(H2O) C 2/m 2/m

77.01.04.02 Clinoptilolite-K (Na,K,Ca)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, C 2, Cm Mono

77.01.04.02a Clinoptilolite-Na! (Na,K,Ca)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m, C 2, Cm Mono

77.01.04.02b Clinoptilolite-Ca! (Ca,Na,K)2-3Al3(Al,Si)2Si13O36•12(H2O) C 2/m 2/m

77.01.04.03 Stilbite-Ca NaCa4[Al8Si28O72]•n(H2O)(n=28-32) C 2/m 2/m

77.01.04.03a Stilbite-Na! Na3Ca3[Al8Si28O72]•n(H2O)(n=28-32) C 2/m 2/m

77.01.04.04 Stellerite CaAl2Si7O18•7(H2O) F mmm 2/m 2/m 2/m

77.01.04.05 Barrerite (Na,K,Ca)2Al2Si7O18•6(H2O) Amma or Ammm 2/m 2/m 2/m

Strunz Class:

09.GE.10 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GE -Chains of T10O20 Tetrahedra

09.GE.10 Stilbite-Ca NaCa4[Al8Si28O72]•n(H2O)(n=28-32) C 2/m 2/m

09.GE.10 Stilbite-Na! Na3Ca3[Al8Si28O72]•n(H2O)(n=28-32) C 2/m 2/m

Other Stilbite-Na Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Stilbite-Na :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Stilbite-Na

Na3Ca3[Al8Si28O72]•n(H2O) (n=28-32)
Dana No: 77.01.04.03a Strunz No: 09.GE.10
Locality:

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