Mineralogy Database

Thornasite Mineral Data

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General Thornasite Information

Help on Chemical  Formula: Chemical Formula: Na12Th3[Si8O19]4•18(H2O)
Help on Composition: Composition: Molecular Weight = 3,410.96 gm
   Sodium     8.09 %  Na   10.90 % Na2O
   Thorium   20.41 %  Th   23.22 % ThO2
   Silicon   26.35 %  Si   56.37 % SiO2
   Hydrogen   1.06 %  H     9.51 % H2O
   Oxygen    44.09 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na12Th3(Si8O19)4•18(H2O)
Help on IMA Status: IMA Status: Approved IMA 1987
Help on Locality: Locality: DeMix quarry, Mt. St. Hilaire, Quebec, Canada. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for its composition (Thorium, Na, Si).
Help on Name Pronunciation: Name Pronunciation: Thornasite + Pronunciation Say THORNASITE
Help on Synonym: Synonym: ICSD 89792
  IMA1985-050
  PDF 40-506
 

Thornasite Image

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  Thornasite

Comments: Opaque thornasite microcrystals.
Location: DeMix-Varennes Quarry, Saint Amable Sill, Varennes, Quebec, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Thornasite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.59264
Help on Cell Dimensions: Cell Dimensions: a = 29.124, c = 17.2602, Z = 6; V = 12,678.81 Den(Calc)= 2.68
Help on Crystal System: Crystal System: Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.27(1), 4.17(0.7), 8.17(0.3),
 

Physical Properties of Thornasite

Help on Cleavage: Cleavage: None
Help on Color: Color: Colorless, Pale green.
Help on Density: Density: 2.62
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Habit: Habit: Anhedral Grains - Granular minerals without the expression of crystal shapes
Help on Habit: Habit: Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Luminescence: Luminescence: Fluorescent, Short UV=bright green, Long UV=bright green.
Help on Luster: Luster: Vitreous - Waxy
Help on Streak: Streak: white
 

Optical Properties of Thornasite

Help on Dichroism (e): Dichroism (e): colorless.
Help on Dichroism (w): Dichroism (w): colorless.
Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.067 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.088 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1907,KPDmeas= 0.195,KC= 0.2091
Ncalc = 1.55 - 1.56
Help on Optical Data: Optical Data: Uniaxial (+), w=1.51, e=1.512, bire=0.0020.
 

Calculated Properties of Thornasite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.52 gm/cc
note: Specific Gravity of Thornasite =2.62 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEThornasite = 448.19 barns/electron
U=PEThornasite x relectron=1,127.79 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 418,148.63 (Gamma Ray American Petroleum Institute Units)
Concentration of Thornasite per GRapi unit = 2.39 (PPM)

Thornasite is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 72.74 ± 18.19 grams of pure Thornasite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 7274.1 ±1818.5 grams of pure Thornasite .

Estimated Radioactivity from Thornasite - strong
Specimen
Size
Weight/Volume
(Sphere)
*
Calculated
Activity
Bequerols
(Bq)
Calculated
Activity
Curies (Ci)
Estimated
Activity
GR(api)
Estimated
Exposure
(mRem**)/hr
If Held in Hand
For One Hour
1000 gm / 9.00 cm 9,142,865 2.47E-04 418,148.63 137.47
100 gm / 4.18 cm 914,287 2.47E-05 41,814.86 13.75
10 gm / 1.94 cm 91,429 2.47E-06 4,181.49 1.37
1 gm / 9.00 mm 9,143 2.47E-07 418.15 0.14
0.1 gm / 4.18 mm 914 2.47E-08 41.81 0.01
0.01 gm / 1.94 mm 91 2.47E-09 4.18 0.00
0.001 gm / 0.90 mm 9 2.47E-10 0.42 0.00

Weight of pure Thornasite in grams (gm) and Calculated Diameter of a Sphere with a Density of 2.62 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem
 

Thornasite Classification

Help on  Dana Class: Dana Class: 72.01.02.01 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
  (72.01)with 4-membered rings
  (72.01.02)Dana Group
 
72.01.02.01 Thornasite Na12Th3[Si8O19]4•18(H2O) R 3c 3 2/m
Help on  Strunz Class: Strunz Class: 09.GF.50 09 - SILICATES (Germanates)
  09.G - Tektosilicates with Zeolitic H2O
  09.GF -Other Rare Zeolites
 
09.GF.50 Thornasite Na12Th3[Si8O19]4•18(H2O) R 3c 3 2/m
 

Other Thornasite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(AmMin, vol 85, p 1521;Dana8) OPTIC PROP.(Am.Min.,Vol.73,p931,1988)
Help on See Also: See Also: Links to other databases for Thornasite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
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 - Uranium Minerals

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Print or Cut-and-Paste your Thornasite Specimen Label here :

Thornasite

Na12Th3[Si8O19]4•18(H2O)
Dana No: 72.01.02.01 Strunz No: 09.GF.50
Locality:

 

Notes:

 

 
   
 


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