Clarkeite Mineral Data

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,KrÃ¸deren, 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 Becquerels (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

Search for Clarkeite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Clarkeite :

A Bijoux Google Search for Clarkeite
Adam's Minerals Google Search for Clarkeite
Cape Minerals Google Search for Clarkeite
Dakota Matrix Minerals Google Search for Clarkeite
Excalibur Mineral Corp. Google Search for Clarkeite
Exceptional Minerals Google Search for Clarkeite
John Betts Fine Minerals Search for Clarkeite
McDougall Minerals Google Search for Clarkeite
Mineral News Website Link
Rock and Mineral Shows Google Search for Clarkeite
Weinrich Minerals, Inc. Google Search for Clarkeite

Ask about Clarkeite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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: