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Soddyite Mineral Data

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General Soddyite Information

Help on Chemical  Formula: Chemical Formula: (UO2)2SiO4•2(H2O)
Help on Composition: Composition: Molecular Weight = 668.17 gm
   Uranium   71.25 %  U    80.83 % UO2
   Silicon    4.20 %  Si    8.99 % SiO2
   Hydrogen   0.60 %  H     5.39 % H2O
   Oxygen    23.95 %  O
            ______        ______ 
            100.00 %       95.21 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: (UO2)2(SiO4)•2(H2O)
Help on Environment: Environment: Mixed with curite in oxidized uranium ores.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1922
Help on Locality: Locality: Shinkolobwe, Shaba, Democratic Republic of the Congo (Zaire). Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Frederick Soddy (1877-1956), British radiochemist and physicist.
Help on Name Pronunciation: Name Pronunciation: Soddyite Say SODDYITE
Help on Synonym: Synonym: ICSD 66313
  PDF 35-491

Soddyite Image

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Comments: Yellow crystals of soddyite.
Location: Swambo mine, Mindingi, Shaba, Democratic Republic of the Congo. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

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Comments: Blocky, tabular crystals of yellow soddyite.
Location: Swambo (Kambove), Shaba (Katanga), Congo (Zaïre). Scale: Picture size 2 mm.
© Paul M. Schumacher

Soddyite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7421:1:1.669
Help on Cell Dimensions: Cell Dimensions: a = 8.32, b = 11.21, c = 18.71, Z = 8; V = 1,745.03 Den(Calc)= 5.09
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: F ddd
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.57(1), 3.36(0.9), 6.28(0.9),

Physical Properties of Soddyite

Help on Cleavage: Cleavage: {001} Perfect, {111} Good
Help on Color: Color: Yellow, Canary yellow, Yellowish green, Yellow.
Help on Density: Density: 4.627
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Pyramidal - Crystals are shaped like pyramids.
Help on Habit: Habit: Striated - Parallel lines on crystal surface or cleavage face.
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luminescence: Luminescence: Fluorescent, Short UV=weak orange yellow, Long UV=weak orange yellow.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: yellow

Optical Properties of Soddyite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.249 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.136 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1339,KPDmeas= 0.1473,KC= 0.1179
Ncalc = 1.55 - 1.6
Help on Optical Data: Optical Data: Biaxial (-), a=1.65-1.654, b=1.685, g=1.699-1.715, bire=0.0490-0.0610
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): pale yellow.
Help on Pleochroism (z): Pleochroism (z): pale yellow green.

Calculated Properties of Soddyite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.30 gm/cc
note: Specific Gravity of Soddyite =5.09 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.007208671
Boson Index = 0.992791329
Help on Photoelectric: Photoelectric: PESoddyite =1,915.19 barns/electron
U=PESoddyite x relectron=8,228.52 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 5,126,250.25 (Gamma Ray American Petroleum Institute Units)
Concentration of Soddyite per GRapi unit = 195.07 (PPB)

Soddyite 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) 5.93 ± 1.48 grams of pure Soddyite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 593.35 ±148.34 grams of pure Soddyite .

Estimated Radioactivity from Soddyite - very strong
Curies (Ci)
If Held in Hand
For One Hour
1000 gm / 7.21 cm 127,534,110 3.45E-03 5,126,250.25 1,685.34
100 gm / 3.35 cm 12,753,411 3.45E-04 512,625.03 168.53
10 gm / 1.55 cm 1,275,341 3.45E-05 51,262.50 16.85
1 gm / 7.21 mm 127,534 3.45E-06 5,126.25 1.69
0.1 gm / 3.35 mm 12,753 3.45E-07 512.63 0.17
0.01 gm / 1.55 mm 1,275 3.45E-08 51.26 0.02
0.001 gm / 0.72 mm 128 3.45E-09 5.13 0.00

Weight of pure Soddyite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.09 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

Soddyite Classification

Help on  Dana Class: Dana Class: (53)Nesosilicate Insular SiO4 Groups and Other Anions of Complex Cations
  (53.03)with (UO2)
  (53.03.03)Other uranyl sillicates Soddyite (UO2)2SiO4•2(H2O) F ddd 2/m 2/m 2/m Uranosilite (UO2)Si7O15 P 22121 2 2 2
Help on  Strunz Class: Strunz Class: 09.AK.05 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AK -Uranyl neso- and polysilicates
09.AK.05 Soddyite (UO2)2SiO4•2(H2O) F ddd 2/m 2/m 2/m

Other Soddyite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Soddyite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - Uranium Minerals

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Dana No: Strunz No: 09.AK.05





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