Coutinhoite Mineral Data


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General Coutinhoite Information
Help on Chemical Formula: Chemical Formula: ThxBa1-2x(H2O)y(UO2)2Si5O13·H2O
Help on Composition: Composition: Molecular Weight = 2,118.94 gm
   Potassium    0.13 %  K     0.16 % K2O
   Barium       1.23 %  Ba    1.37 % BaO
   Calcium      0.08 %  Ca    0.11 % CaO
   Thorium      3.29 %  Th    3.74 % ThO2
   Uranium     67.40 %  U    76.46 % UO2
   Silicon      6.52 %  Si   13.95 % SiO2
   Phosphorus   0.12 %  P     0.27 % P2O5
   Hydrogen     0.27 %  H     2.43 % H2O
   Oxygen      20.97 %  O
              ______        ______ 
              100.00 %       98.49 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Th0.3Ba0.19K0.07Ca0.043(UO2)2Si4.92P0.08O12.91·2.86(H2O)
Help on Environment: Environment: Secondary hydrothermal mineral in a pegmatite from the oxidation of uraninite. Isostructural with weeksite.
Help on IMA Status: IMA Status: Approved IMA 2004 (Dana # Added)
Help on Locality: Locality: Corrego do Urcum granitic pegmatite, Lavra Urucum, Galileia Co., Minas Gerais, Brazil. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Jose Moacyr Vianna Coutinho (1924-), Professor of Mineralogy and Petrography the the Instituto de Geociencieas of Universidad de Sao Paulo, Brazil.
Help on Synonym: Synonym: IMA2003-025
 

Coutinhoite Image

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Coutinhoite

Comments: New mineral, IMA 2003-025, from this pegmatite. This is a co-type specimen. Flaky crystals of choutinhoite to less than 0.25mm in gelatin capsule.
Location: Lavra do Urucum, Serra do Urucum, Galileia, Minas Gerais, Brazil. Scale: Crystal size 0.25mm.
© Tom Loomis / Dakota Matrix
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Coutinhoite

Comments: Irregular aggregate of yellow coutinhoite. (AmMin, v 89, p 721).
Location: Urucum mine, Galil?ia, Minas Gerais, Brazil. Scale: See Image.
© American Mineralogist

Coutinhoite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.9981:1:2.519
Help on Cell Dimensions: Cell Dimensions: a = 14.1676, b = 14.1935, c = 35.754, Z = 8; V = 7,189.69 Den(Calc)= 3.91
Help on Crystal System: Crystal System: Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: C mmb
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.059(1)(020), 3.528(0.86)(040), 2.904(0.78)(2.2.10),3.188(0.73)(2.0.10), 5.563(0.59)(024), 3.287(0.57)(404), 4.581(0.47)(206), 2.981(0.46)(424),
 

Physical Properties of Coutinhoite

Help on Color: Color: Yellow.
Help on Diaphaniety: Diaphaniety: Transparent to Translucent
Help on Habit: Habit: Flakes - Flat, thin crystals or aggregates.
Help on Habit: Habit: Scaly - Morphology like fish scales.
Help on Hardness: Hardness: 1.5 - Between Talc and Gypsum
Help on Luster: Luster: Waxy
Help on Streak: Streak: yellow
 

Optical Properties of Coutinhoite

Help on Gladstone-Dale: Gladstone-Dale: CI calc= -0.303 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1599,KC= 0.1228
Help on Optical Data: Optical Data: Biaxial (-), a=1.62, b=1.627, g=1.629, bire=0.0090, 2V(Calc)=56, 2V(Meas)=40. Dispersion r < v strong.
 

Calculated Properties of Coutinhoite

Help on Electron Density: Electron Density:

relectron=3.28 gm/cc
note: rCoutinhoite =3.91 gm/cc.
Help on Fermion Index Fermion Index Fermion Index = 0.01019
Boson Index = 0.98981
Help on Photoelectric: Photoelectric:

PECoutinhoite =1,909.34 barns/electron
U=PECoutinhoite x relectron=6,269.44 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 4,883,482.22 (Gamma Ray American Petroleum Institute Units)

Coutinhoite 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) 6.23 ± 1.56 grams of pure Coutinhoite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 622.85 ±155.71 grams of pure Coutinhoite .

Estimated Radioactivity from Coutinhoite - 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 / 7.88 cm 122,118,216 3.30E-03 4,883,482.22 1,605.53
100 gm / 3.66 cm 12,211,822 3.30E-04 488,348.22 160.55
10 gm / 1.70 cm 1,221,182 3.30E-05 48,834.82 16.06
1 gm / 7.88 mm 122,118 3.30E-06 4,883.48 1.61
0.1 gm / 3.66 mm 12,212 3.30E-07 488.35 0.16
0.01 gm / 1.70 mm 1,221 3.30E-08 48.83 0.02
0.001 gm / 0.79 mm 122 3.30E-09 4.88 0.00

Weight of pure Coutinhoite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.91 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
 

Coutinhoite Classification
Help on Dana Class: Dana Class: 53.3.2.4 (53)Nesosilicate Insular SiO4 Groups and Other Anions of Complex Cations
  (53.3)with (UO2)
  (53.3.2)Weeksite group
 
53.3.2.1 Weeksite K2(UO2)2Si6O15·4(H2O) C mmb 2/m 2/m 2/m
 
53.3.2.2 Haiweeite Ca[(UO2)2Si5O12(OH)2]·3(H2O) C mcm 2/m 2/m 2/m
 
53.3.2.3 Metahaiweeite Ca(UO2)2Si6O15·n(H2O),n<5 P 2/c ? 2/m
 
53.3.2.4 Coutinhoite ! ThxBa1-2x(H2O)y(UO2)2Si5O13·H2O C mmb 2/m 2/m 2/m
Help on Strunz Class: Strunz Class: VIII/H.37-15 VIII - Silicates
  VIII/H - Phyllosilicates (layered) Mica minerals with other simple layers, [Si6O15]6- and others
  VIII/H.37 - Weeksite series
 
VIII/H.37-10 Weeksite K2(UO2)2Si6O15·4(H2O) C mmb 2/m 2/m 2/m
 
VIII/H.37-15 Coutinhoite ThxBa1-2x(H2O)y(UO2)2Si5O13·H2O C mmb 2/m 2/m 2/m
 

Other Coutinhoite Information
Help on References: References: NAME( AmMin, v 89, p 721) PHYS. PROP.(AmMin, v 89, p 721) OPTIC PROP.(AmMin, v 89, p 721)
Help on See Also: See Also: Links to other databases for Coutinhoite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -MinDAT 6 -MinMax(Deutsch) 7 -MinMax(English) 8 -Mineralienatlas (Deutsch) 9 -QUT Mineral Atlas 10 - Uranium Minerals

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Coutinhoite

ThxBa1-2x(H2O)y(UO2)2Si5O13·H2O
Dana No: 53.3.2.4 Strunz No: VIII/H.37-15
Locality:

 

Notes:

 
 
   
 
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