Vyacheslavite Mineral Data

General Vyacheslavite Information

Chemical Formula:

U++++(PO4)(OH)•2.5(H2O)

Composition:

Molecular Weight = 395.05 gm

Uranium 60.25 % U 68.35 % UO₂

Phosphorus 7.84 % P 17.97 % P₂O₅

Hydrogen 1.53 % H 13.68 % H₂O

Oxygen 30.38 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

U(PO₄)(OH)•2.5(H₂O)

Environment:

Found on quartz crystals associated with octahedral pyrite.

IMA Status:

Approved IMA 1984

Locality:

Uzbekistan. Link to MinDat.org Location Data.

Name Origin:

Named for Vyacheslav Gavilovich Melkov (1911-1991), Russian mineralogist.

Name Pronunciation:

Vyacheslavite + Pronunciation

Vyacheslavite Crystallography

Axial Ratios:

a:b:c =0.7648:1:1.3604

Cell Dimensions:

a = 6.96, b = 9.1, c = 12.38, Z = 6; V = 784.10 Den(Calc)= 5.02

Crystal System:

Orthorhombic Space Group: C mcm, C mc2₁, C 2cm

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

By Intensity(I/I_o): 6.19(1), 2.69(0.7), 4.56(0.6),

Physical Properties of Vyacheslavite

Cleavage:

{010} Distinct

Color:

Green, Dark green.

Density:

4.9 - 5.01, Average = 4.95

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Spherical - Spherical, rounded aggregates.

Habit:

Tabular - Form dimensions are thin in one direction.

Streak:

green

Optical Properties of Vyacheslavite

Gladstone-Dale:

CI meas= 0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1433,KPDmeas= 0.1451,KC= 0.1477
Ncalc = 1.72 - 1.74

Optical Data:

Biaxial (-), a=1.7, b=1.726-1.729, g=1.729-1.731, bire=0.0290-0.0310

Pleochroism (x):

weak green.

Pleochroism (y):

weak green.

Pleochroism (z):

weak green.

Calculated Properties of Vyacheslavite

Electron Density:

Bulk Density (Electron Density)=4.34 gm/cc
note: Specific Gravity of Vyacheslavite =4.96 gm/cc.

Fermion Index:

Fermion Index = 0.0044863483
Boson Index = 0.9955136517

Photoelectric:

PE_{Vyacheslavite}=1,561.22 barns/electron
U=PE_{Vyacheslavite} x r_electron=6,775.43 barns/cc.

Radioactivity:

GRapi = 4,498,260.74 (Gamma Ray American Petroleum Institute Units)
Concentration of Vyacheslavite per GRapi unit = 222.31 (PPB)

Vyacheslavite 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) 6.76 ± 1.69 grams of pure Vyacheslavite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 676.19 ±169.05 grams of pure Vyacheslavite .

**Estimated Radioactivity from Vyacheslavite** - 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 / 7.28 cm	107,853,755	2.91E-03	4,498,260.74	1,478.88
100 gm / 3.38 cm	10,785,376	2.91E-04	449,826.07	147.89
10 gm / 1.57 cm	1,078,538	2.91E-05	44,982.61	14.79
1 gm / 7.28 mm	107,854	2.91E-06	4,498.26	1.48
0.1 gm / 3.38 mm	10,785	2.91E-07	449.83	0.15
0.01 gm / 1.57 mm	1,079	2.91E-08	44.98	0.01
0.001 gm / 0.73 mm	108	2.91E-09	4.50	0.00

Weight of pure Vyacheslavite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.96 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

Vyacheslavite Classification

Dana Class:

40.04.08.03 (40)Hydrated Phosphates, etc

(40.04)where A+++ XO4 ï¿½ x(H2O)

(40.04.08)Ningyoite Group

40.04.08.01 Ningyoite (U,Ca,Ce)2(PO4)2•1-2(H2O) P 222 2 2 2

40.04.08.02 Lermontovite U(PO4)(OH)•(H2O)(?) C cca 2/m 2/m 2/m

40.04.08.03 Vyacheslavite U(PO4)(OH)•2.5(H2O) C mcm, C mc2₁, C 2cm Ortho

Strunz Class:

08.DN.20 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DN -With only large cations

08.DN.20 Vyacheslavite U(PO4)(OH)•2.5(H2O) C mcm, C mc2₁, C 2cm Ortho

Other Vyacheslavite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Vyacheslavite :
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 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - Uranium Minerals

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Print or Cut-and-Paste your Vyacheslavite Specimen Label here :

Vyacheslavite

U++++(PO4)(OH)•2.5(H2O)
Dana No: 40.04.08.03 Strunz No: 08.DN.20
Locality:

Notes:

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