Nielsbohrite Mineral Data

General Nielsbohrite Information

Chemical Formula:

K(UO2)3(AsO4)(OH)4•H2O

Composition:

Molecular Weight = 1,093.26 gm

Potassium 1.54 % K 1.85 % K₂O

Uranium 68.80 % U 78.05 % UO₂

Arsenic 6.76 % As 10.38 % As₂O₅

Hydrogen 0.55 % H 4.94 % H₂O

Oxygen 22.34 % O

______ ______

100.00 % 95.22 % = TOTAL OXIDE

Empirical Formula:

K_0.43(UO₂)_3.16(AsO₄)_0.98(OH)₄•(H₂O)

Environment:

Secondary mineral assemblage of the uranium deposit. New structure type.

IMA Status:

Approved IMA 2006 (Dana # Added)

Locality:

Menzenschwand, Southern Black Forest, Baden-Wï¿½rttemberg, Germany Link to MinDat.org Location Data.

Name Origin:

Named for Niels Henrik David Bohr (1885-1962), Danish physicist and Nobel Prize winner in Physics (1922) who made fundamental contributions to understanding atomic structure and qua ntum mechanics.

Synonym:

IMA2002-045b

Nielsbohrite Crystallography

Axial Ratios:

a:b:c =0.7167:1:1.1811

Cell Dimensions:

a = 8.193, b = 11.43, c = 13.5, Z = 4; V = 1,264.22 Den(Calc)= 5.74

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: C ccm

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 6.03(1), 3.33(0.8), 6.71(0.8),3.78(0.7), 2.96(0.6), 1.942(0.5), 2.63(0.5), 2.88(0.4),

Physical Properties of Nielsbohrite

Cleavage:

None

Color:

Yellow.

Diaphaneity:

Transparent

Fracture:

Brittle - Irregular - Very brittle fracture producing irregular fragments

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Hardness:

2 - Gypsum

Luster:

Vitreous - Dull

Streak:

pale yellow

Optical Properties of Nielsbohrite

Gladstone-Dale:

CI calc= -0.151 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1327,KC= 0.1153
Ncalc = 1.66

Optical Data:

Biaxial (-), a=1.756, b=1.764, g=1.765, bire=0.0090, 2V(Calc)=38, 2V(Meas)=35. Dispersion strong, r > v.

Calculated Properties of Nielsbohrite

Electron Density:

Bulk Density (Electron Density)=4.83 gm/cc
note: Specific Gravity of Nielsbohrite =5.74 gm/cc.

Fermion Index:

Fermion Index = 0.005063593
Boson Index = 0.994936407

Photoelectric:

PE_Nielsbohrite=1,861.86 barns/electron
U=PE_Nielsbohrite x r_electron=8,985.70 barns/cc.

Radioactivity:

GRapi = 4,930,850.22 (Gamma Ray American Petroleum Institute Units)
Concentration of Nielsbohrite per GRapi unit = 202.80 (PPB)

Nielsbohrite 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) 6.17 ± 1.54 grams of pure Nielsbohrite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 616.86 ±154.22 grams of pure Nielsbohrite .

**Estimated Radioactivity from Nielsbohrite** - 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 / 6.93 cm	123,154,109	3.33E-03	4,930,850.22	1,621.10
100 gm / 3.22 cm	12,315,411	3.33E-04	493,085.02	162.11
10 gm / 1.49 cm	1,231,541	3.33E-05	49,308.50	16.21
1 gm / 6.93 mm	123,154	3.33E-06	4,930.85	1.62
0.1 gm / 3.22 mm	12,315	3.33E-07	493.09	0.16
0.01 gm / 1.49 mm	1,232	3.33E-08	49.31	0.02
0.001 gm / 0.69 mm	123	3.33E-09	4.93	0.00

Weight of pure Nielsbohrite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.74 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

Nielsbohrite Classification

Dana Class:

42.01.03.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.01)where (A)3 (XO4) Zq ï¿½ x(H2O)

(42.01.03)Dana Group

42.01.03.01 Nielsbohrite! K(UO2)3(AsO4)(OH)4•H2O C ccm 2/m 2/m 2/m

Strunz Class:

08.EC.45 08 - PHOSPHATES, ARSENATES, VANADATES

08.E - Uranyl Phosphates and Arsenates

08.EC -UO2:RO4 = 3:2

08.EC.45 Nielsbohrite! K(UO2)3(AsO4)(OH)4•H2O C ccm 2/m 2/m 2/m

Other Nielsbohrite Information

References:

NAME( EurJMin, v21:515) PHYS. PROP.(EurJMin, v21:515) OPTIC PROP.(EurJMin, v21:515)

See Also:

Links to other databases for Nielsbohrite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Nielsbohrite

K(UO2)3(AsO4)(OH)4•H2O
Dana No: 42.01.03.01 Strunz No: 08.EC.45
Locality:

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