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Coffinite Mineral Data

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General Coffinite Information

Help on Chemical  Formula: Chemical Formula: U(SiO4)1-x(OH)4x
Help on Composition: Composition: Molecular Weight = 327.71 gm
   Uranium   72.63 %  U    82.40 % UO2
   Silicon    7.71 %  Si   16.50 % SiO2
   Hydrogen   0.12 %  H     1.10 % H2O
   Oxygen    19.53 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: U(SiO4)0.9(OH)0.4
Help on Environment: Environment: In Colorado Plateau-type black unoxidized U-V deposits, replacing organic material in sandstone.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1956
Help on Locality: Locality: La Sal No. 2 mine, Beaver Mesa, Gateway district, Mesa County, New Mexico, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Reuben Clare Coffin (1886-1972), Tulsa, Oklahoma, USA, pioneer geologist in the study of uranium deposits of the Colorado Plateau.
Help on Synonym: Synonym: ICSD 15484
  PDF 11-420

Coffinite Image

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Comments: Black, interstitial coffinite cementing a sub-angular quartzose sandstone. Schumacher Collection.
Location: Temple Mountain, San Rafael District (San Rafael Swell), Emery Co., Utah, USA. Scale: Picture size 5 mm.
© Paul M. Schumacher

Coffinite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.90187
Help on Cell Dimensions: Cell Dimensions: a = 6.93, c = 6.25, Z = 3; V = 300.16 Den(Calc)= 5.44
Help on Crystal System: Crystal System: Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: I 41/amd
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.47(1), 4.66(1), 2.64(0.7),

Physical Properties of Coffinite

Help on Cleavage: Cleavage: None
Help on Color: Color: Black, Pale brown, Dark brown.
Help on Density: Density: 5.1
Help on Diaphaneity: Diaphaneity: Subtranslucent to Opaque
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Hardness: Hardness: 5-6 - Between Apatite and Orthoclase
Help on Luster: Luster: Subadamantine
Help on Streak: Streak: grayish black

Optical Properties of Coffinite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.205 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.129 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.136,KPDmeas= 0.1451,KC= 0.1205
Ncalc = 1.61 - 1.66
Help on Optical Data: Optical Data: Uniaxial (+/-), a=1.73-1.75, b=1.73-1.75, bire=0.0000.

Calculated Properties of Coffinite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.55 gm/cc
note: Specific Gravity of Coffinite =5.44 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0089257303
Boson Index = 0.9910742697
Help on Photoelectric: Photoelectric: PECoffinite =1,971.22 barns/electron
U=PECoffinite x relectron=8,965.99 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 5,176,587.32 (Gamma Ray American Petroleum Institute Units)
Concentration of Coffinite per GRapi unit = 193.18 (PPB)

Coffinite 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) 5.88 ± 1.47 grams of pure Coffinite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 587.58 ±146.90 grams of pure Coffinite .

Estimated Radioactivity from Coffinite - very strong
Curies (Ci)
If Held in Hand
For One Hour
1000 gm / 7.05 cm 130,016,209 3.51E-03 5,176,587.32 1,701.89
100 gm / 3.27 cm 13,001,621 3.51E-04 517,658.73 170.19
10 gm / 1.52 cm 1,300,162 3.51E-05 51,765.87 17.02
1 gm / 7.05 mm 130,016 3.51E-06 5,176.59 1.70
0.1 gm / 3.27 mm 13,002 3.51E-07 517.66 0.17
0.01 gm / 1.52 mm 1,300 3.51E-08 51.77 0.02
0.001 gm / 0.71 mm 130 3.51E-09 5.18 0.00

Weight of pure Coffinite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.44 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

Coffinite Classification

Help on  Dana Class: Dana Class: (51)Nesosilicate Insular SiO4 Groups Only
  (51.05)with cations in >[6] coordination
  (51.05.02)Zircon group Zircon ZrSiO4 I 41/amd 4/m 2/m 2/m Hafnon HfSiO4 I 41/amd 4/m 2/m 2/m Thorite ThSiO4 I 41/amd 4/m 2/m 2/m Coffinite U(SiO4)1-x(OH)4x I 41/amd 4/m 2/m 2/m Thorogummite Th(SiO4)1-x(OH)4x I 41/amd 4/m 2/m 2/m IMA2008-035! CeSiO4 I 41/amd 4mm
Help on  Strunz Class: Strunz Class: 09.AD.30 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AD -Nesosilicates without additional anions;
09.AD.30 Coffinite U(SiO4)1-x(OH)4x I 41/amd 4/m 2/m 2/m
09.AD.30 Hafnon HfSiO4 I 41/amd 4/m 2/m 2/m
09.AD.30 Thorite ThSiO4 I 41/amd 4/m 2/m 2/m
09.AD.30 Thorogummite Th(SiO4)1-x(OH)4x I 41/amd 4/m 2/m 2/m
09.AD.30 Zircon ZrSiO4 I 41/amd 4/m 2/m 2/m
09.AD.30 IMA2008-035! CeSiO4 I 41/amd 4mm

Other Coffinite Information

Help on References: References: NAME( AntBidBlaNic2) 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 Coffinite :
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 - University of Colorado - Mineral Structure Data
16 - Uranium Minerals

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Dana No: Strunz No: 09.AD.30





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