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 % Al2 O3
Silicon 21.48 % Si 45.94 % SiO2
Hydrogen 1.54 % H 13.78 % H2 O
Oxygen 53.01 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
CaAl2 Si3 O10 •3(H2 O)
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
X Ray Diffraction:
By Intensity(I/Io ): 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:
PEScolecite = 2.50 barns/electronU=PEScolecite x r Electron 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 4 2d 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 21 21 2 2 2 2
77.01.05.07 Gonnardite Na2CaAl4Si6O20•7(H2O) I 4 2d 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 21 21 21 2 2 2
Strunz Class:
09.GA.05 09 - SILICATES (Germanates)
09.G - Tektosilicates with Zeolitic H2O
09.GA -Zeolites with T5O10 Units � The Fibrous Zeolites
09.GA.05 Gonnardite Na2CaAl4Si6O20•7(H2O) I 4 2d 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 4 2d 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
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