Gadolinite-(Ce) Mineral Data

General Gadolinite-(Ce) Information

Chemical Formula:

(Ce,La,Nd,Y)2Fe++Be2Si2O10

Composition:

Molecular Weight = 571.37 gm

Lanthanum 10.94 % La 12.83 % La₂O₃

Cerium 16.68 % Ce 19.53 % Ce₂O₃

La,Ce,Pr,Nd,Sm, 17.89 % RE 20.88 % REE₂O₃

Yttrium 4.98 % Y 6.32 % Y₂O₃

Magnesium 0.17 % Mg 0.28 % MgO

Titanium 0.08 % Ti 0.14 % TiO₂

Manganese 0.96 % Mn 1.24 % MnO

Beryllium 2.93 % Be 8.14 % BeO

Aluminum 0.05 % Al 0.09 % Al₂O₃

Iron 7.23 % Fe 9.31 % FeO

Silicon 9.93 % Si 21.24 % SiO₂

Boron 0.15 % B 0.49 % B₂O₃

Oxygen 28.00 % O

______ ______

100.00 % 100.49 % = TOTAL OXIDE

Empirical Formula:

Ce_0.68La_0.45Y_0.32REE_0.71Fe²⁺_0.74Mn²⁺_0.1Mg_0.04Ti_0.01Be_1.86B_0.08Al_0.01Si_2.02O₁₀

Environment:

In syenite pegmatite veins along a contact between basalt and monzonite.

IMA Status:

Approved IMA 1978

Locality:

From a dump at Buer, nine km southeast of Skien, Bjorkendalen region, and in the Bakken quarry, Tvedalen, Norway. Link to MinDat.org Location Data.

Name Origin:

Named for its cerium content and the relationship to gadolinite-(Y).

Name Pronunciation:

Gadolinite-(Ce) + Pronunciation

Gadolinite-(Ce) Image

Images:

Gadolinite-(Ce)

Comments: Sharp, well crystallized single crystal of brown gadolinite.
Location: Buer, BjÃ¸rkedalen, Porsgrunn, Telemark, Norway. Scale: 18x14x8 mm.
© John Betts - Fine Minerals

Gadolinite-(Ce) Crystallography

Axial Ratios:

a:b:c =0.6358:1:1.3205

Cell Dimensions:

a = 4.82, b = 7.58, c = 10.01, Z = 2; beta = 90.47° V = 365.71 Den(Calc)= 5.19

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 2.88(1), 4.81(0.9), 2.6(0.8),

Physical Properties of Gadolinite-(Ce)

Cleavage:

None

Color:

Black.

Density:

4.2

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

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

Hardness:

6.5-7 - Pyrite-Quartz

Luster:

Vitreous (Glassy)

Streak:

greenish gray

Optical Properties of Gadolinite-(Ce)

Gladstone-Dale:

CI meas= -0.086 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.122 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1503,KPDmeas= 0.1857,KC= 0.1711
Ncalc = 1.72 - 1.89

Optical Data:

Isotropic, n=1.78.

Calculated Properties of Gadolinite-(Ce)

Electron Density:

Bulk Density (Electron Density)=3.82 gm/cc
note: Specific Gravity of Gadolinite-(Ce) =4.20 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_{Gadolinite-(Ce)}= 257.52 barns/electron
U=PE_{Gadolinite-(Ce)} x r_electron= 982.71 barns/cc.

Radioactivity:

GRapi = 44,167.77 (Gamma Ray American Petroleum Institute Units)
Concentration of Gadolinite-(Ce) per GRapi unit = 22.64 (PPM)

Gadolinite-(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) 688.66 ±172.17 grams of pure Gadolinite-(Ce) .

**Estimated Radioactivity from Gadolinite-(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 / 7.69 cm	1,020,842	2.76E-05	44,167.77	14.52
100 gm / 3.57 cm	102,084	2.76E-06	4,416.78	1.45
10 gm / 1.66 cm	10,208	2.76E-07	441.68	0.15
1 gm / 7.69 mm	1,021	2.76E-08	44.17	0.01
0.1 gm / 3.57 mm	102	2.76E-09	4.42	0.00
0.01 gm / 1.66 mm	10	2.76E-10	0.44	0.00
0.001 gm / 0.77 mm	1	2.76E-11	0.04	0.00

Weight of pure Gadolinite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.20 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 ( 2.28 % Th) From Sum REE Elements (45.51 % REE)

Gadolinite-(Ce) Classification

Dana Class:

54.02.01b.02 (54)Nesosilicate Borosilicates and Some Beryllosilicates

(54.02)with B in [4] coordination

(54.02.01b)Datolite group (Homilite series)

54.02.01b.01 Bakerite Ca4B4(BO4)(SiO4)3(OH)3•(H2O) P 2₁/c 2/m

54.02.01b.02 Gadolinite-(Ce) (Ce,La,Nd,Y)2FeBe2Si2O10 P 2₁/c 2/m

54.02.01b.03 Gadolinite-(Y) Y2FeBe2Si2O10 P 2₁/a 2/m

54.02.01b.04 Calciogadolinite? CaREE(Fe)Be2Si2O10 P 2₁/a 2/m

54.02.01b.05 Homilite Ca2(Fe,Mg)B2Si2O10 P 2₁/a 2/m

54.02.01b.06 Minasgeraisite-(Y) CaY2Be2Si2O10 P 2₁/a 2/m

Strunz Class:

09.AJ.20 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AJ -Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra,

09.AJ.20 Bakerite Ca4B4(BO4)(SiO4)3(OH)3•(H2O) P 2₁/c 2/m

09.AJ.20 Calcybeborosilite-(Y)! (REE,Ca)2[](B,Be)2(SiO4)2(OH,O)2 P 2₁/a 2/m

09.AJ.20 Calciogadolinite? CaREE(Fe)Be2Si2O10 P 2₁/a 2/m

09.AJ.20 Datolite CaBSiO4(OH) P 2₁/c 2/m

09.AJ.20 Hingganite-(Yb) (Yb,Y)2([])Be2Si2O8(OH)2 P 2₁/a 2/m

09.AJ.20 Homilite Ca2(Fe,Mg)B2Si2O10 P 2₁/a 2/m

09.AJ.20 Gadolinite-(Ce) (Ce,La,Nd,Y)2FeBe2Si2O10 P 2₁/c 2/m

09.AJ.20 Gadolinite-(Y) Y2FeBe2Si2O10 P 2₁/a 2/m

09.AJ.20 Hingganite-(Ce) (Ce,Ca)2([],Fe)Be2Si2O8[(OH),O]2 P 2₁/a 2/m

09.AJ.20 Hingganite-(Y) Y2([])Be2Si2O8(OH)2 P 2₁/a 2/m

09.AJ.20 Melanocerite-(Ce) (Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O)(?) Unk (HEX-R) Trig

09.AJ.20 Minasgeraisite-(Y) CaY2Be2Si2O10 P 2₁/a 2/m

Other Gadolinite-(Ce) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Gadolinite-(Ce) :
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 (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Gadolinite-(Ce)

(Ce,La,Nd,Y)2Fe++Be2Si2O10
Dana No: 54.02.01b.02 Strunz No: 09.AJ.20
Locality:

Notes:

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