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Clarkeite Mineral Data

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General Clarkeite Information

Help on Chemical  Formula: Chemical Formula: (Na,Ca,Pb)(UO2)O(OH)•0-1(H2O)
Help on Composition: 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
Help on Empirical Formula: Empirical Formula: Na0.7Pb0.1Ca0.1(UO2)0.9O0.9(OH)1.1•0.1(H2O)
Help on Environment: Environment: Replacing uraninite, as a late-stage hydrothermal alteration product.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1931
Help on Locality: Locality: Spruce Pine district, from the Deer Park and other mines, Mitchell County, North Carolina, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Frank Wigglesworth Clarke (1847-1931), prominent American geochemist of the US Geological Survey.
Help on Synonym: Synonym: ICSD 83456
  PDF 8-315

Clarkeite Image

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

Clarkeite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:4.48406
Help on Cell Dimensions: Cell Dimensions: a = 3.954, c = 17.73, Z = 3; V = 240.06 Den(Calc)= 6.61
Help on Crystal System: Crystal System: Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.195(1), 5.903(0.64), 3.365(0.56),

Physical Properties of Clarkeite

Help on Cleavage: Cleavage: None
Help on Color: Color: Brown, Brownish yellow, Dark brown, Reddish brown.
Help on Density: Density: 6.39
Help on Diaphaneity: Diaphaneity: Translucent to Opaque
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Hardness: Hardness: 4-4.5 - Between Fluorite and Apatite
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Resinous
Help on Magnetism: Magnetism: Nonmagnetic
Help on Streak: Streak: yellowish brown

Optical Properties of Clarkeite

Help on Gladstone-Dale: 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
Help on Optical Data: 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.
Help on Pleochroism (x): Pleochroism (x): dark orange.
Help on Pleochroism (y): Pleochroism (y): less dark orange.
Help on Pleochroism (z): Pleochroism (z): more dark orange.

Calculated Properties of Clarkeite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.52 gm/cc
note: Specific Gravity of Clarkeite =6.61 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEClarkeite =1,944.09 barns/electron
U=PEClarkeite x relectron=10739.76 barns/cc.
Help on Radioactivity: 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
Curies (Ci)
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

Help on  Dana Class: Dana Class: (05)Oxides Containing Uranium and Thorium
  (05.04)with alkaline-earth elements (hydrated)
  (05.04.01)Dana Group Clarkeite (Na,Ca,Pb)(UO2)O(OH)•0-1(H2O) R 3m 3 2/m
Help on  Strunz Class: 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

Help on References: References: NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: 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

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Dana No: Strunz No: 04.GC.05





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