Scolecite Mineral Data

General Scolecite Information

Chemical Formula:

CaAl2Si3O10•3(H2O)

Composition:

Molecular Weight = 392.34 gm

Calcium 10.22 % Ca 14.29 % CaO

Aluminum 13.75 % Al 25.99 % Al₂O₃

Silicon 21.48 % Si 45.94 % SiO₂

Hydrogen 1.54 % H 13.78 % H₂O

Oxygen 53.01 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaAl₂Si₃O₁₀•3(H₂O)

Environment:

Low temperature alteration of basalts and related rocks.

IMA Status:

Valid Species (Pre-IMA) 1813

Locality:

Kaiserstuhl in Baden. Link to MinDat.org Location Data.

Name Origin:

From the Greek, skolec = 'worm' in reference to the mineral's reaction to the blowpipe flame.

Name Pronunciation:

Scolecite + Pronunciation

Synonym:

ICSD 30967

PDF 41-1355

Scolecite Image

Images:

Scolecite

Comments: Delicate cluster spray of colorless transparent acicular crystals of scolecite. The scolecites measure to 3 mm in thickness.
Location: Nasik district, Maharashtra, India. Scale: 5 x 3.5 x 9.5 cm.
© Dan Weinrich

Scolecite Crystallography

Axial Ratios:

a:b:c =0.3438:1:0.5151

Cell Dimensions:

a = 6.516, b = 18.948, c = 9.761, Z = 4; beta = 108.98° V = 1,139.62 Den(Calc)= 2.29

Crystal System:

Monoclinic - Domatic H-M Symbol (m) Space Group: Cc

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

By Intensity(I/I_o): 2.882(1), 5.85(1), 6.59(0.9),

Physical Properties of Scolecite

Cleavage:

{110} Perfect

Color:

Brownish, Colorless, White.

Density:

2.16 - 2.4, Average = 2.28

Diaphaneity:

Transparent to subtranslucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

5-5.5 - Apatite-Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Scolecite

Gladstone-Dale:

CI meas= 0 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2252,KPDmeas= 0.2262,KC= 0.2262
Ncalc = 1.49 - 1.54

Optical Data:

Biaxial (-), a=1.507-1.513, b=1.516-1.52, g=1.517-1.521, bire=0.0080-0.0100, 2V(Calc)=36-40, 2V(Meas)=36-56. Dispersion relatively strong.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Scolecite

Electron Density:

Bulk Density (Electron Density)=2.30 gm/cc
note: Specific Gravity of Scolecite =2.28 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Scolecite= 2.50 barns/electron
U=PE_Scolecite x rElectron Density= 5.75 barns/cc.

Radioactivity:

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

Scolecite Classification

Dana Class:

77.01.05.05 (77)Tectosilicate Zeolite group

(77.01)true zeolites

(77.01.05)Natrolite and related species

77.01.05.01 Natrolite Na2[Al2Si3O10]•2(H2O) F dd2 mm2

77.01.05.02 Tetranatrolite? Na2[Al2Si3O10]•2(H2O) I 42d 4 2m

77.01.05.03 Paranatrolite Na2[Al2Si3O10]•3(H2O) Cc m

77.01.05.04 Mesolite Na2Ca2Al6Si9O30•8(H2O) C 2 2

77.01.05.05 Scolecite CaAl2Si3O10•3(H2O) Cc m

77.01.05.06 Edingtonite BaAl2Si3O10•4(H2O) P 2₁2₁2 2 2 2

77.01.05.07 Gonnardite Na2CaAl4Si6O20•7(H2O) I 42d 4 2m

77.01.05.08 Cowlesite CaAl2Si3O10•5-6(H2O) P 222₁, P mmm, Pmm2 Ortho

77.01.05.09 Thomsonite-Ca NaCa2Al5Si5O20•6(H2O) Pncn 2/m 2/m 2/m

77.01.05.10 Thomsonite-Sr! (Sr,Ca)2Na[Al5Si5O20]•7(H2O) Pcnn 2/m 2/m 2/m

77.01.05.11 Nabesite! Na2BeSi4O10•4(H2O) P 2₁2₁2₁ 2 2 2

Strunz Class:

09.GA.05 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GA -Zeolites with T5O10 Units ï¿½ The Fibrous Zeolites

09.GA.05 Gonnardite Na2CaAl4Si6O20•7(H2O) I 42d 4 2m

09.GA.05 Mesolite Na2Ca2Al6Si9O30•8(H2O) C 2 2

09.GA.05 Natrolite Na2[Al2Si3O10]•2(H2O) F dd2 mm2

09.GA.05 Paranatrolite Na2[Al2Si3O10]•3(H2O) Cc m

09.GA.05 Scolecite CaAl2Si3O10•3(H2O) Cc m

09.GA.05 Tetranatrolite? Na2[Al2Si3O10]•2(H2O) I 42d 4 2m

Other Scolecite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

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Scolecite

CaAl2Si3O10•3(H2O)
Dana No: 77.01.05.05 Strunz No: 09.GA.05
Locality:

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