Demesmaekerite Mineral Data

General Demesmaekerite Information

Chemical Formula:

Pb2Cu5(UO2)2(SeO3)6(OH)6•2(H2O)

Composition:

Molecular Weight = 2,172.01 gm

Uranium 21.92 % U 24.86 % UO₂

Copper 14.63 % Cu 18.31 % CuO

Hydrogen 0.46 % H 4.15 % H₂O

Lead 19.08 % Pb 20.55 % PbO

Selenium 21.81 % Se 30.65 % SeO₂

Oxygen 22.10 % O

______ ______

100.00 % 98.53 % = TOTAL OXIDE

Empirical Formula:

Pb₂Cu₅(UO₂)₂(SeO₃)₆(OH)₆•2(H₂O)

Environment:

Lower part of the oxidation zone.

IMA Status:

Approved IMA 1965

Locality:

Musonoi mine, Kolwezi, Shaba, Zaire. Link to MinDat.org Location Data.

Name Origin:

Named for Gaston Demesmaeker (1911-), Belgian mining geologist, who studied the Shikolobwe uranium deposits.

Name Pronunciation:

Demesmaekerite + Pronunciation

Synonym:

ICSD 37177

PDF 18-692

Demesmaekerite Image

Images:

Demesmaekerite Malachite

Comments: Pale green crystals of demesmaekerite on dark green malachite.
Location: Musonoi Mine, Katanga, Democratic Republic of the Congo. Scale: Crystal Size 3mm.
© John Veevaert

Images:

Demesmaekerite

Comments: Tabular, light green and spear-shaped dark greenish brown demesmaekerite crystals.
Location: Musonoi mine, Kolwezi, Shaba (Katanga), Congo (Zaïre). Scale: Picture size 3 mm.
© Paul M. Schumacher

Demesmaekerite Crystallography

Axial Ratios:

a:b:c =1.1908:1:0.5617

Cell Dimensions:

a = 11.955, b = 10.039, c = 5.639, Z = 1; alpha = 89.78°, beta = 100.37°, gamma = 91.33° V = 665.53 Den(Calc)= 5.42

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 2.97(1), 5.42(0.8), 5.89(0.6),

Physical Properties of Demesmaekerite

Cleavage:

None

Color:

Brown, Brownish green, Green, Bottle green.

Density:

5.28

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Hardness:

3-4 - Calcite-Fluorite

Optical Properties of Demesmaekerite

Gladstone-Dale:

CI meas= -0.051 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.161,KPDmeas= 0.1652,KC= 0.1572
Ncalc = 1.83 - 1.85

Optical Data:

Biaxial (+), a=1.835, g=1.91, bire=0.0750

Calculated Properties of Demesmaekerite

Electron Density:

Bulk Density (Electron Density)=4.73 gm/cc
note: Specific Gravity of Demesmaekerite =5.42 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_{Demesmaekerite}= 930.80 barns/electron
U=PE_{Demesmaekerite} x r_electron=4,399.20 barns/cc.

Radioactivity:

GRapi = 1,629,108.74 (Gamma Ray American Petroleum Institute Units)
Concentration of Demesmaekerite per GRapi unit = 613.83 (PPB)

Demesmaekerite 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) 18.67 ± 4.67 grams of pure Demesmaekerite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 1867.1 ±466.77 grams of pure Demesmaekerite .

**Estimated Radioactivity from Demesmaekerite** - 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 / 7.06 cm	39,232,958	1.06E-03	1,629,108.74	535.60
100 gm / 3.28 cm	3,923,296	1.06E-04	162,910.87	53.56
10 gm / 1.52 cm	392,330	1.06E-05	16,291.09	5.36
1 gm / 7.06 mm	39,233	1.06E-06	1,629.11	0.54
0.1 gm / 3.28 mm	3,923	1.06E-07	162.91	0.05
0.01 gm / 1.52 mm	392	1.06E-08	16.29	0.01
0.001 gm / 0.71 mm	39	1.06E-09	1.63	0.00

Weight of pure Demesmaekerite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.42 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

Demesmaekerite Classification

Dana Class:

34.07.06.01 (34)Selenites - Tellurites - Sulfites

(34.07)Dana Type

(34.07.06)Dana Group

34.07.06.01 Demesmaekerite Pb2Cu5(UO2)2(SeO3)6(OH)6•2(H2O) P1 1

Strunz Class:

04.JJ.20 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JJ -Selenites with additional anions, with H2O

04.JJ.20 Demesmaekerite Pb2Cu5(UO2)2(SeO3)6(OH)6•2(H2O) P1 1

Other Demesmaekerite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Demesmaekerite :
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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Demesmaekerite

Pb2Cu5(UO2)2(SeO3)6(OH)6•2(H2O)
Dana No: 34.07.06.01 Strunz No: 04.JJ.20
Locality:

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