Clarkeite Mineral Data

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General Clarkeite Information

Chemical Formula:

(Na,Ca,Pb)(UO2)O(OH)•0-1(H2O)

Composition:

Molecular Weight = 318.75 gm

Sodium 5.05 % Na 6.81 % Na₂O

Calcium 1.26 % Ca 1.76 % CaO

Uranium 67.21 % U 76.24 % UO₂

Hydrogen 0.41 % H 3.67 % H₂O

Lead 6.50 % Pb 7.00 % PbO

Oxygen 19.58 % O

______ ______

100.00 % 95.48 % = TOTAL OXIDE

Empirical Formula:

Na_0.7Pb_0.1Ca_0.1(UO₂)_0.9O_0.9(OH)_1.1•0.1(H₂O)

Environment:

Replacing uraninite, as a late-stage hydrothermal alteration product.

IMA Status:

Valid Species (Pre-IMA) 1931

Locality:

Spruce Pine district, from the Deer Park and other mines, Mitchell County, North Carolina, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Frank Wigglesworth Clarke (1847-1931), prominent American geochemist of the US Geological Survey.

Synonym:

ICSD 83456

PDF 8-315

Clarkeite Image

Images:

Clarkeite

Comments: Massive orange clarkeite.
Location: Bjertnes,Krøderen, Buskerud, Norway. Scale: Picture size 8 mm.
© Thomas Witzke / Abraxas-Verlag

Clarkeite Crystallography

Axial Ratios:

a:c = 1:4.48406

Cell Dimensions:

a = 3.954, c = 17.73, Z = 3; V = 240.06 Den(Calc)= 6.61

Crystal System:

Trigonal - Hexagonal ScalenohedralH-M Symbol (3 2/m) Space Group: R 3m

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

By Intensity(I/I_o): 3.195(1), 5.903(0.64), 3.365(0.56),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Finch R J , Ewing R C , American Mineralogist , 82 (1997) p.607-619, Clarkeite: New chemical and structural data

Physical Properties of Clarkeite

Cleavage:

None

Color:

Brown, Brownish yellow, Dark brown, Reddish brown.

Density:

6.39

Diaphaneity:

Translucent to Opaque

Fracture:

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

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

4-4.5 - Between Fluorite and Apatite

Luminescence:

Non-fluorescent.

Luster:

Resinous

Magnetism:

Nonmagnetic

Streak:

yellowish brown

Optical Properties of Clarkeite

Gladstone-Dale:

CI meas= -0.457 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.409 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1615,KPDmeas= 0.1671,KC= 0.1147
Ncalc = 1.73 - 1.76

Optical Data:

Biaxial (-), a=1.997, b=2.098, g=2.108, bire=0.1110, 2V(Calc)=32, 2V(Meas)=30-50. Dispersion relatively weak.

Pleochroism (x):

dark orange.

Pleochroism (y):

less dark orange.

Pleochroism (z):

more dark orange.

Calculated Properties of Clarkeite

Electron Density:

Bulk Density (Electron Density)=5.52 gm/cc
note: Specific Gravity of Clarkeite =6.61 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Clarkeite=1,944.09 barns/electron
U=PE_Clarkeite x r_electron=10739.76 barns/cc.

Radioactivity:

GRapi = 4,787,702.56 (Gamma Ray American Petroleum Institute Units)
Concentration of Clarkeite per GRapi unit = 208.87 (PPB)

Clarkeite 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) 6.35 ± 1.59 grams of pure Clarkeite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 635.31 ±158.83 grams of pure Clarkeite .

**Estimated Radioactivity from Clarkeite** - 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 / 6.61 cm	120,300,859	3.25E-03	4,787,702.56	1,574.04
100 gm / 3.07 cm	12,030,086	3.25E-04	478,770.26	157.40
10 gm / 1.42 cm	1,203,009	3.25E-05	47,877.03	15.74
1 gm / 6.61 mm	120,301	3.25E-06	4,787.70	1.57
0.1 gm / 3.07 mm	12,030	3.25E-07	478.77	0.16
0.01 gm / 1.42 mm	1,203	3.25E-08	47.88	0.02
0.001 gm / 0.66 mm	120	3.25E-09	4.79	0.00

Weight of pure Clarkeite in grams (gm) and Calculated Diameter of a Sphere with a Density of 6.61 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

Clarkeite Classification

Dana Class:

05.04.01.01 (05)Oxides Containing Uranium and Thorium

(05.04)with alkaline-earth elements (hydrated)

(05.04.01)Dana Group

05.04.01.01 Clarkeite (Na,Ca,Pb)(UO2)O(OH)•0-1(H2O) R 3m 3 2/m

Strunz Class:

04.GC.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.G - Uranyl Hydroxides

04.GC -With additional cations; with UO2(O,OH)6 hexagonal polyhedra

04.GC.05 Clarkeite (Na,Ca,Pb)(UO2)O(OH)•0-1(H2O) R 3m 3 2/m

Other Clarkeite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Clarkeite :
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 Clarkeite Specimen Label here :

Clarkeite

(Na,Ca,Pb)(UO2)O(OH)•0-1(H2O)
Dana No: 05.04.01.01 Strunz No: 04.GC.05
Locality:

Notes: