Thomsonite-Ca Mineral Data

General Thomsonite-Ca Information

Chemical Formula:

NaCa2Al5Si5O20•6(H2O)

Composition:

Molecular Weight = 806.56 gm

Sodium 2.85 % Na 3.84 % Na₂O

Calcium 9.94 % Ca 13.91 % CaO

Aluminum 16.73 % Al 31.60 % Al₂O₃

Silicon 17.41 % Si 37.25 % SiO₂

Hydrogen 1.50 % H 13.40 % H₂O

Oxygen 51.58 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaCa₂Al₅Si₅O₂₀•6(H₂O)

Environment:

Found in cavities in lava and in amygdaloidal igneous rocks.

IMA Status:

Valid Species (Pre-IMA) 1820

Locality:

Kilpatrick Hills, Bunbarton, Scotland. Link to MinDat.org Location Data.

Name Origin:

Named after the Scottish chemist, T. Thomson (1773-1852).

Name Pronunciation:

Thomsonite-Ca + Pronunciation

Synonym:

Bagotite

Thomsonite

Thomsonite-Ca Image

Images:

Click Here for Larger Thomsonite-Ca Image

Thomsonite-Ca Stilbite-Ca

Comments: Peach colored stilbite crystals to 3.5 cm in size is hosting two finely crystallized balls of powdery white thomsonite.
Location: Near Jalgaon, Maharashtra State, India. Scale: Picture size 15 cm.
© Dan Weinrich

Thomsonite-Ca Crystallography

Axial Ratios:

a:b:c =1.0036:1:1.0145

Cell Dimensions:

a = 13.1043, b = 13.0569, c = 13.2463, Z = 4; V = 2,266.46 Den(Calc)= 2.36

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pncn

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

By Intensity(I/I_o): 2.857(1), 2.944(1), 4.625(1),

Crystal Structure:

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Stahl K , Kvick A , Smith J V , Acta Crystallographica, Section C , 46 (1990) p.1370-1373, Thomsonite, a neutron diffraction study at 13 K, Sample: T = 13 K

Physical Properties of Thomsonite-Ca

Cleavage:

{101} Perfect, {100} Good

Color:

Colorless, Greenish, Yellow, White, Pink.

Density:

2.3 - 2.4, Average = 2.34

Diaphaneity:

Transparent to translucent

Fracture:

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

Habit:

Fibrous - Crystals made up of fibers.

Habit:

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

Habit:

Spherical - Spherical, rounded aggregates.

Hardness:

5-5.5 - Apatite-Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Thomsonite-Ca

Gladstone-Dale:

CI meas= 0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.012 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2222,KPDmeas= 0.2232,KC= 0.225
Ncalc = 1.52 - 1.54

Optical Data:

Biaxial (+), a=1.511-1.53, b=1.513-1.532, g=1.516-1.545, bire=0.0050-0.0150, 2V(Calc)=44-80, 2V(Meas)=44-75. Dispersion distinct to strong, r > v.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Calculated Properties of Thomsonite-Ca

Electron Density:

Bulk Density (Electron Density)=2.37 gm/cc
note: Specific Gravity of Thomsonite-Ca =2.35 gm/cc.

Fermion Index:

Fermion Index = 0.0085147492
Boson Index = 0.9914852508

Photoelectric:

PE_{Thomsonite-Ca}= 2.44 barns/electron
U=PE_{Thomsonite-Ca} x rElectron Density= 5.78 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Thomsonite-Ca is Not Radioactive

Thomsonite-Ca Classification

Dana Class:

77.01.05.09 (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.10 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GA -Zeolites with T5O10 Units – The Fibrous Zeolites

09.GA.10 Thomsonite-Ca NaCa2Al5Si5O20•6(H2O) Pncn 2/m 2/m 2/m

09.GA.10 Thomsonite-Sr! (Sr,Ca)2Na[Al5Si5O20]•7(H2O) Pcnn 2/m 2/m 2/m

Other Thomsonite-Ca Information

See Also:

Links to other databases for Thomsonite-Ca :
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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Print or Cut-and-Paste your Thomsonite-Ca Specimen Label here :

Thomsonite-Ca

NaCa2Al5Si5O20•6(H2O)
Dana No: 77.01.05.09 Strunz No: 09.GA.10
Locality:

Notes: