Soddyite Mineral Data

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General Soddyite Information

Chemical Formula:

(UO2)2SiO4•2(H2O)

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

Empirical Formula:

(UO₂)₂(SiO₄)•2(H₂O)

Environment:

Mixed with curite in oxidized uranium ores.

IMA Status:

Valid Species (Pre-IMA) 1922

Locality:

Shinkolobwe, Shaba, Democratic Republic of the Congo (Zaire). Link to MinDat.org Location Data.

Name Origin:

Named for Frederick Soddy (1877-1956), British radiochemist and physicist.

Name Pronunciation:

Soddyite

Synonym:

ICSD 66313

PDF 35-491

Soddyite Image

Images:

Soddyite

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

Images:

Soddyite

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

Soddyite Crystallography

Axial Ratios:

a:b:c =0.7421:1:1.669

Cell Dimensions:

a = 8.32, b = 11.21, c = 18.71, Z = 8; V = 1,745.03 Den(Calc)= 5.09

Crystal System:

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

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

By Intensity(I/I_o): 4.57(1), 3.36(0.9), 6.28(0.9),

Crystal Structure:

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Demartin F , Gramaccioli C M , Pilati T , Acta Crystallographica, Section C , 48 (1992) p.1-4, The importance of accurate crystal structure determination, of uranium minerals. II. Soddyite (UO2)2(SiO4)*2H2O, Locality: Democratic Republic of the Congo

Physical Properties of Soddyite

Cleavage:

{001} Perfect, {111} Good

Color:

Yellow, Canary yellow, Yellowish green, Yellow.

Density:

4.627

Diaphaneity:

Transparent to translucent

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Pyramidal - Crystals are shaped like pyramids.

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

3-4 - Calcite-Fluorite

Luminescence:

Fluorescent, Short UV=weak orange yellow, Long UV=weak orange yellow.

Luster:

Vitreous (Glassy)

Streak:

yellow

Optical Properties of Soddyite

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

Optical Data:

Biaxial (-), a=1.65-1.654, b=1.685, g=1.699-1.715, bire=0.0490-0.0610

Pleochroism (x):

colorless.

Pleochroism (y):

pale yellow.

Pleochroism (z):

pale yellow green.

Calculated Properties of Soddyite

Electron Density:

Bulk Density (Electron Density)=4.30 gm/cc
note: Specific Gravity of Soddyite =5.09 gm/cc.

Fermion Index:

Fermion Index = 0.007208671
Boson Index = 0.992791329

Photoelectric:

PE_Soddyite=1,915.19 barns/electron
U=PE_Soddyite x r_electron=8,228.52 barns/cc.

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
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 / 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

Dana Class:

53.03.03.01 (53)Nesosilicate Insular SiO4 Groups and Other Anions of Complex Cations

(53.03)with (UO2)

(53.03.03)Other uranyl sillicates

53.03.03.01 Soddyite (UO2)2SiO4•2(H2O) F ddd 2/m 2/m 2/m

53.03.03.02 Uranosilite (UO2)Si7O15 P 22121 2 2 2

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

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

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
16 - WWW-MINCRYST

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

Soddyite

(UO2)2SiO4•2(H2O)
Dana No: 53.03.03.01 Strunz No: 09.AK.05
Locality:

Notes: