Petscheckite Mineral Data

General Petscheckite Information

Chemical Formula:

U++++Fe++(Nb,Ta)2O8

Composition:

Molecular Weight = 651.70 gm

Uranium 36.52 % U 41.43 % UO₂

Tantalum 13.88 % Ta 16.95 % Ta₂O₅

Niobium 21.38 % Nb 30.59 % Nb₂O₅

Iron 8.57 % Fe 11.02 % FeO

Oxygen 19.64 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

UFe²⁺Nb_1.5Ta_0.5O₈

Environment:

Petscheckite is hypothesized on theoretical grounds, having altered to oxypetscheckite and hydroxypetscheckite.

IMA Status:

Approved IMA 1978

Locality:

Antsaoka I pegmatite, Berere district, Madagascar. Link to MinDat.org Location Data.

Name Origin:

Named for Eckhard Petsch (1939-), of Idar-Oberstein, Germany, who was a noteworthy prospector in Madagascar.

Name Pronunciation:

Petscheckite + Pronunciation

Synonym:

Hydroxypetscheckite

Oxypetscheckite

Petscheckite Crystallography

Axial Ratios:

a:c = 1:0.62616

Cell Dimensions:

a = 6.42, c = 4.02, Z = 1; V = 143.49 Den(Calc)= 7.54

Crystal System:

Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: P 31m

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

By Intensity(I/I_o): 3.21(1), 4.02(1), 2.51(0.8),

Physical Properties of Petscheckite

Cleavage:

None

Color:

Black.

Density:

5.5

Diaphaneity:

Opaque

Habit:

Metamict - Mineral originally crystalline, now amorphous due to radiation damage.

Hardness:

5 - Apatite

Luster:

Metallic

Streak:

brown black

Optical Properties of Petscheckite

Optical Data:

NCalc= 2.28 - from Gladstone-Dale relationship (KC = 0.1697) where Ncalc=Dcalc*KC+1
NCalc= 1.93 - from Gladstone-Dale relationship (KC = 0.1697) where Ncalc=Dmeas*KC+1

Calculated Properties of Petscheckite

Electron Density:

Bulk Density (Electron Density)=6.48 gm/cc
note: Specific Gravity of Petscheckite =7.54 gm/cc.

Fermion Index:

Fermion Index = 0.0045573699
Boson Index = 0.9954426301

Photoelectric:

PE_Petscheckite=1,168.76 barns/electron
U=PE_Petscheckite x r_electron=7,572.38 barns/cc.

Radioactivity:

GRapi = 2,675,160.58 (Gamma Ray American Petroleum Institute Units)
Concentration of Petscheckite per GRapi unit = 373.81 (PPB)

Petscheckite 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) 11.37 ± 2.84 grams of pure Petscheckite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 1137.0 ±284.25 grams of pure Petscheckite .

**Estimated Radioactivity from Petscheckite** - 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 / 6.33 cm	65,378,044	1.77E-03	2,675,160.58	879.50
100 gm / 2.94 cm	6,537,804	1.77E-04	267,516.06	87.95
10 gm / 1.36 cm	653,780	1.77E-05	26,751.61	8.80
1 gm / 6.33 mm	65,378	1.77E-06	2,675.16	0.88
0.1 gm / 2.94 mm	6,538	1.77E-07	267.52	0.09
0.01 gm / 1.36 mm	654	1.77E-08	26.75	0.01
0.001 gm / 0.63 mm	65	1.77E-09	2.68	0.00

Weight of pure Petscheckite in grams (gm) and Calculated Diameter of a Sphere with a Density of 7.54 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

Petscheckite Classification

Dana Class:

08.01.09.02 (08)Multiple Oxides with Nb, Ta, and Ti

(08.01)where A BO4

(08.01.09)Dana Group

08.01.09.01 Liandratite U(Nb,Ta)2O8 P 31m 3 2/m

08.01.09.02 Petscheckite UFe(Nb,Ta)2O8 P 31m 3 2/m

Strunz Class:

04.DH.35 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DH -With large (ï¿½ medium-sized) cations; sheets of edge-sharing octahedra

04.DH.35 Liandratite U(Nb,Ta)2O8 P 31m 3 2/m

04.DH.35 Petscheckite UFe(Nb,Ta)2O8 P 31m 3 2/m

Other Petscheckite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8)

See Also:

Links to other databases for Petscheckite :
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

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Petscheckite

U++++Fe++(Nb,Ta)2O8
Dana No: 08.01.09.02 Strunz No: 04.DH.35
Locality:

Notes:

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