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Dumontite Mineral Data

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General Dumontite Information

Help on Chemical  Formula: Chemical Formula: Pb2(UO2)3O2(PO4)2•5(H2O)
Help on Composition: Composition: Molecular Weight = 1,536.50 gm
   Uranium     46.47 %  U    52.72 % UO2
   Phosphorus   4.03 %  P     9.24 % P2O5
   Hydrogen     0.66 %  H     5.86 % H2O
   Lead        26.97 %  Pb   29.05 % PbO
   Oxygen      21.87 %  O
              ______        ______ 
              100.00 %       96.88 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Pb2(UO2)3O2(PO4)2•5(H2O)
Help on Environment: Environment: Secondary lead-uranium mineral
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1924
Help on Locality: Locality: Kasolo (Shinkolobwe), Katanga (Shaba), Congo (Za�re) Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for A.H. Dumont
Help on Name Pronunciation: Name Pronunciation: Dumontite + Pronunciation Say DUMONTITE
Help on Synonym: Synonym: ICSD 202795
  PDF 12-158
 

Dumontite Image

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  Dumontite

Comments: Bright yellow acicular crystals of dumontite on matrix.
Location: Shinkolobwe mine, Tantara, Shaba, Democratic Republic of the Congo. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Dumontite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.4877:1:0.4196
Help on Cell Dimensions: Cell Dimensions: a = 8.16, b = 16.73, c = 7.02, Z = 2; beta = 110° V = 900.55 Den(Calc)= 5.67
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.27(1), 2.94(0.85), 3(0.85),
 

Physical Properties of Dumontite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Golden yellow, Light yellow.
Help on Density: Density: 5.65
Help on Diaphaneity: Diaphaneity: Translucent
Help on Hardness: Hardness: 2-3 - Gypsum-Calcite
Help on Luminescence: Luminescence: Fluorescent, Short UV=weak green, Long UV=weak green.
Help on Streak: Streak: light yellow
 

Optical Properties of Dumontite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.201 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.197 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1534,KPDmeas= 0.154,KC= 0.1282
Ncalc = 1.72 - 1.73
Help on Optical Data: Optical Data: Biaxial (+), a=1.85, b=1.87, g=1.89, bire=0.0400
 

Calculated Properties of Dumontite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.78 gm/cc
note: Specific Gravity of Dumontite =5.67 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.06
Boson Index = 0.94
Help on Photoelectric: Photoelectric: PEDumontite =1,741.15 barns/electron
U=PEDumontite x relectron=8,327.07 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 3,341,365.42 (Gamma Ray American Petroleum Institute Units)
Concentration of Dumontite per GRapi unit = 299.28 (PPB)

Dumontite 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) 9.10 ± 2.28 grams of pure Dumontite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 910.31 ±227.58 grams of pure Dumontite .

Estimated Radioactivity from Dumontite - 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 / 6.96 cm 83,189,999 2.25E-03 3,341,365.42 1,098.53
100 gm / 3.23 cm 8,319,000 2.25E-04 334,136.54 109.85
10 gm / 1.50 cm 831,900 2.25E-05 33,413.65 10.99
1 gm / 6.96 mm 83,190 2.25E-06 3,341.37 1.10
0.1 gm / 3.23 mm 8,319 2.25E-07 334.14 0.11
0.01 gm / 1.50 mm 832 2.25E-08 33.41 0.01
0.001 gm / 0.70 mm 83 2.25E-09 3.34 0.00

Weight of pure Dumontite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.67 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
 

Dumontite Classification

Help on  Dana Class: Dana Class: 42.04.05.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.04)where (AB)5 (XO4)2 Zq � x(H2O)
  (42.04.05)Dumontite Group
 
42.04.05.01 Dumontite Pb2(UO2)3O2(PO4)2•5(H2O) P 21/m 2/m
 
42.04.05.02 Hugelite Pb2(UO2)3(AsO4)2(OH)4•3(H2O) P 21/m 2/m
 
42.04.05.03 Bergenite Ca2Ba4[(UO3)2O2(PO4)2]3(H2O)16 P 21/c 2/m
Help on  Strunz Class: Strunz Class: 08.EC.15 08 - PHOSPHATES, ARSENATES, VANADATES
  08.E - Uranyl Phosphates and Arsenates
  08.EC -UO2:RO4 = 3:2
 
08.EC.15 Dumontite Pb2(UO2)3O2(PO4)2•5(H2O) P 21/m 2/m
 
08.EC.15 Hugelite Pb2(UO2)3(AsO4)2(OH)4•3(H2O) P 21/m 2/m
 

Other Dumontite Information

Help on References: References: PHYS. PROP.(Enc. of Minerals,2nd ed.,1990;Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Dumontite :
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 Dumontite Specimen Label here :

Dumontite

Pb2(UO2)3O2(PO4)2•5(H2O)
Dana No: 42.04.05.01 Strunz No: 08.EC.15
Locality:

 

Notes:

 

 
   
 


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