Fergusonite-beta-(Ce) Mineral Data

General Fergusonite-beta-(Ce) Information

Chemical Formula:

(Ce,La,Nd)NbO4

Composition:

Molecular Weight = 288.78 gm

Lanthanum 9.62 % La 11.28 % La₂O₃

Cerium 19.41 % Ce 22.73 % Ce₂O₃

Praeseodymium 4.88 % Pr 5.71 % Pr₂O₃

La,Ce,Pr,Nd,Sm, 4.99 % RE 5.82 % REE₂O₃

Niobium 28.95 % Nb 41.42 % Nb₂O₅

Neodymium 9.99 % Nd 11.65 % Nd₂O₃

Oxygen 22.16 % O

______ ______

100.00 % 98.61 % = TOTAL OXIDE

Empirical Formula:

La_0.2Ce_0.4Pr_0.1Nd_0.2REE_0.1Nb_0.9O₄

Environment:

In magnesian skarn around carbonatite-derived dolomitic marble.

IMA Status:

Approved IMA 1973

Locality:

Bayan Obo Fe-Nb-REE deposit, 130 km north of Baotaou, Inner Mongolia. Link to MinDat.org Location Data.

Name Origin:

Named for the dimorphous relationship to fergusonite-(Ce).

Name Pronunciation:

Fergusonite-beta-(Ce) + Pronunciation

Fergusonite-beta-(Ce) Image

Images:

Fergusonite-beta-(Ce)

Comments: Dark brown vitreous amorphous (metamict) fragments of fergusonite-beta-(Ce).
Location: Amherst County, Virginia, USA. Scale: See Image.
© Rruff Database

Fergusonite-beta-(Ce) Crystallography

Axial Ratios:

a:b:c =0.4576:1:0.4832

Cell Dimensions:

a = 5.19, b = 11.34, c = 5.48, Z = 4; beta = 95.57° V = 321.00 Den(Calc)= 5.98

Crystal System:

Monoclinic - Sphenoidal H-M Symbol (2) Space Group: I2

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

By Intensity(I/I_o): 1.965(1), 3.058(1), 3.24(1),

Physical Properties of Fergusonite-beta-(Ce)

Color:

Red, Reddish brown.

Density:

5.34

Diaphaneity:

Subtranslucent to Opaque

Fracture:

Brittle - Subconchoidal - Brittle frature with subconchoidal fragments

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

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

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5.5-6.5 - Knife Blade-Pyrite

Luster:

Vitreous - Greasy

Streak:

pale rose

Optical Properties of Fergusonite-beta-(Ce)

Gladstone-Dale:

CI meas= -0.126 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.006 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1931,KPDmeas= 0.2163,KC= 0.192
Ncalc = 2.03 - 2.15

Optical Data:

Isotropic, n=2.155.

Calculated Properties of Fergusonite-beta-(Ce)

Electron Density:

Bulk Density (Electron Density)=5.28 gm/cc
note: Specific Gravity of Fergusonite-beta-(Ce) =5.98 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Fergusonite-beta-(Ce)}= 313.39 barns/electron
U=PE_{Fergusonite-beta-(Ce)} x r_electron=1,654.84 barns/cc.

Radioactivity:

GRapi = 46,060.19 (Gamma Ray American Petroleum Institute Units)
Concentration of Fergusonite-beta-(Ce) per GRapi unit = 21.71 (PPM)

Fergusonite-beta-(Ce) 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) 660.37 ±165.09 grams of pure Fergusonite-beta-(Ce) .

**Estimated Radioactivity from Fergusonite-beta-(Ce)** - weak
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 / 6.84 cm	1,095,395	2.96E-05	46,060.19	15.14
100 gm / 3.17 cm	109,540	2.96E-06	4,606.02	1.51
10 gm / 1.47 cm	10,954	2.96E-07	460.60	0.15
1 gm / 6.84 mm	1,095	2.96E-08	46.06	0.02
0.1 gm / 3.17 mm	110	2.96E-09	4.61	0.00
0.01 gm / 1.47 mm	11	2.96E-10	0.46	0.00
0.001 gm / 0.68 mm	1	2.96E-11	0.05	0.00

Weight of pure Fergusonite-beta-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.98 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
Estimated Thorium Activity ( 2.44 % Th) From Sum REE Elements (48.88 % REE)

Fergusonite-beta-(Ce) Classification

Dana Class:

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

(08.01)where A BO4

(08.01.02)Fergusonite-beta Grup (Monoclinic)

08.01.02.01 Fergusonite-beta-(Y) YNbO4 I2 2

08.01.02.02 Fergusonite-beta-(Ce) (Ce,La,Nd)NbO4 I2 2

08.01.02.03 Fergusonite-beta-(Nd) (Nd,Ce)NbO4 I2 2

Strunz Class:

04.DG.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

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

04.DG -With large (� medium-sized) cations; chains of edge-sharing octahedra

04.DG.10 Fergusonite-beta-(Nd) (Nd,Ce)NbO4 I2 2

04.DG.10 Fergusonite-beta-(Y) YNbO4 I2 2

04.DG.10 Fergusonite-beta-(Ce) (Ce,La,Nd)NbO4 I2 2

04.DG.10 Yttrotantalite-(Y) (Y,U,Fe)(Ta,Nb)O4 I2/a 2/m

Other Fergusonite-beta-(Ce) Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Fergusonite-beta-(Ce) :
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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Print or Cut-and-Paste your Fergusonite-beta-(Ce) Specimen Label here :

Fergusonite-beta-(Ce)

(Ce,La,Nd)NbO4
Dana No: 08.01.02.02 Strunz No: 04.DG.10
Locality:

Notes:

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