Ursilite Mineral Data

General Ursilite Information

Chemical Formula:

(Mg,Ca)4[(UO2)4(OH)5/(Si2O5)5.5]•13(H2O)

Composition:

Molecular Weight = 2,261.26 gm

Calcium 1.77 % Ca 2.48 % CaO

Magnesium 3.22 % Mg 5.35 % MgO

Uranium 42.11 % U 47.77 % UO₂

Silicon 13.66 % Si 29.23 % SiO₂

Hydrogen 1.38 % H 12.35 % H₂O

Oxygen 37.85 % O

______ ______

100.00 % 97.17 % = TOTAL OXIDE

Empirical Formula:

Mg₃Ca(UO₂)₄(OH)₅(Si₂O₅)_5.5•13(H₂O)

Environment:

Oxidized zone oI a uranium-coal deposit in fractures in the coal 20-50 m. below the surface. Both Ca and Mg dominant forms are present.

IMA Status:

Not Approved IMA - Published 1957

Locality:

Not Stated. Link to MinDat.org Location Data.

Name Origin:

Named for the composition (U, Si).

Ursilite Crystallography

Crystal System:

Orthorhombic Space Group: Unk

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

By Intensity(I/I_o): 3.06(1), 4.98(1), 2.07(0.9),2.3(0.9), 3.37(0.8), 4.58(0.8), 1.798(0.6), 1.981(0.6), 2.42(0.6),

Physical Properties of Ursilite

Color:

Green, Pale green.

Density:

3.03 - 3.254, Average = 3.14

Hardness:

2-3 - Gypsum-Calcite

Luminescence:

Fluorescent, Short UV=medium yellow green.

Streak:

light yellow

Optical Properties of Ursilite

Gladstone-Dale:

CI meas= -0.05 (Good) - where the CI = (1-KPDmeas/KC)
KPDmeas= 0.1748,KC= 0.1664
Ncalc = 1.5 - 1.54

Optical Data:

Biaxial (-), a=1.543-1.548, g=1.55-1.556, bire=0.0070-0.0080

Pleochroism (x):

pale green.

Pleochroism (z):

green.

Calculated Properties of Ursilite

Electron Density:

Bulk Density (Electron Density)=2.88 gm/cc
note: Specific Gravity of Ursilite =3.14 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Ursilite=1,042.45 barns/electron
U=PE_Ursilite x r_electron=3,004.12 barns/cc.

Radioactivity:

GRapi = 3,291,773.62 (Gamma Ray American Petroleum Institute Units)
Concentration of Ursilite per GRapi unit = 303.79 (PPB)

Ursilite 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) 9.24 ± 2.31 grams of pure Ursilite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 924.02 ±231.01 grams of pure Ursilite .

**Estimated Radioactivity from Ursilite** - 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 / 8.47 cm	75,368,801	2.04E-03	3,291,773.62	1,082.23
100 gm / 3.93 cm	7,536,880	2.04E-04	329,177.36	108.22
10 gm / 1.83 cm	753,688	2.04E-05	32,917.74	10.82
1 gm / 8.47 mm	75,369	2.04E-06	3,291.77	1.08
0.1 gm / 3.93 mm	7,537	2.04E-07	329.18	0.11
0.01 gm / 1.83 mm	754	2.04E-08	32.92	0.01
0.001 gm / 0.85 mm	75	2.04E-09	3.29	0.00

Weight of pure Ursilite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.14 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

Ursilite Classification

Dana Class:

51.00.00.00 (51)Nesosilicate Minerals

(51.00)Without Dana Classification Numbers

(51.00.00)Uranyl nesosilicate

51.00.00.00 Hydrougrandite? (Ca,Mg,Fe)3(Fe,Al)2(SiO4)3-x(OH)4x I a3d 4/m 3 2/m

51.00.00.00 Ursilite* (Mg,Ca)4[(UO2)4(OH)5/(Si2O5)5.5]•13(H2O) Unk Ortho

Strunz Class:

09.AK.35 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AK -Uranyl neso- and polysilicates

09.AK.35 Ursilite* (Mg,Ca)4[(UO2)4(OH)5/(Si2O5)5.5]•13(H2O) Unk Ortho

Other Ursilite Information

References:

NAME( AmMin,v44:464) PHYS. PROP.(AmMin,v44:464) OPTIC PROP.(AmMin,v44:464)

See Also:

Links to other databases for Ursilite :
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 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - Uranium Minerals

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

Ursilite

(Mg,Ca)4[(UO2)4(OH)5/(Si2O5)5.5]•13(H2O)
Dana No: 51.00.00.00 Strunz No: 09.AK.35
Locality:

Notes:

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