Ilimaussite-(Ce) Mineral Data

General Ilimaussite-(Ce) Information

Chemical Formula:

(Ba,Na)10K3Na4.5Ce5(Nb,Ti)6[Si12O36][Si9O18(O,OH)24]O6

Composition:

Molecular Weight = 4,253.30 gm

Potassium 3.25 % K 3.92 % K₂O

Barium 22.05 % Ba 24.62 % BaO

Sodium 3.79 % Na 5.11 % Na₂O

Strontium 0.06 % Sr 0.07 % SrO

Lanthanum 2.65 % La 3.10 % La₂O₃

Cerium 6.72 % Ce 7.87 % Ce₂O₃

Praeseodymium 2.15 % Pr 2.52 % Pr₂O₃

Thorium 1.04 % Th 1.18 % ThO₂

Titanium 2.11 % Ti 3.51 % TiO₂

Manganese 0.23 % Mn 0.33 % Mn₂O₃

Niobium 7.47 % Nb 10.69 % Nb₂O₅

Aluminum 0.20 % Al 0.38 % Al₂O₃

Iron 1.37 % Fe 1.95 % Fe₂O₃

Silicon 13.66 % Si 29.21 % SiO₂

Hydrogen 0.48 % H 4.30 % H₂O

Neodymium 1.05 % Nd 1.23 % Nd₂O₃

Oxygen 31.20 % O

Fluorine 0.52 % F 0.52 % F

- % F -0.22 % -O=F₂

______ ______

100.00 % 100.31 % = TOTAL OXIDE

Empirical Formula:

Ba_6.83K_3.54Na_7.02Sr_0.03Ce_2.04La_0.81Nd_0.315(Pr_0.13)Th_0.19Fe³⁺_1.04Mn³⁺_0.18Nb_3.42Ti_1.87 Si_20.68Al_0.32O_62.64(OH)_20.29F_1.17

Environment:

Analcime-ussingite pegmatite.

IMA Status:

Approved IMA 1968

Locality:

Ilimaussaq alkaline complex, South Greenland. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Ilimaussite-(Ce) + Pronunciation

Ilimaussite-(Ce) Crystallography

Axial Ratios:

a:c = 1:5.66852

Cell Dimensions:

a = 10.77, c = 61.05, Z = 3; V = 6,132.65 Den(Calc)= 3.45

Crystal System:

Trigonal - Pyramidal H-M Symbol (3) Space Group: R 32

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

By Intensity(I/I_o): 2.67(1), 3.25(0.6), 3.12(0.5),

Physical Properties of Ilimaussite-(Ce)

Color:

Brownish yellow, Yellowish white.

Density:

3.6

Diaphaneity:

Transparent to Subtranslucent

Hardness:

4 - Fluorite

Luster:

Earthy (Dull)

Streak:

white

Optical Properties of Ilimaussite-(Ce)

Gladstone-Dale:

CI meas= 0.03 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.012 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2006,KPDmeas= 0.1922,KC= 0.1982
Ncalc = 1.68 - 1.71

Optical Data:

Uniaxial (+), w=1.689, e=1.695, bire=0.0060.

Calculated Properties of Ilimaussite-(Ce)

Electron Density:

Bulk Density (Electron Density)=3.19 gm/cc
note: Specific Gravity of Ilimaussite-(Ce) =3.45 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_{Ilimaussite-(Ce)}= 195.79 barns/electron
U=PE_{Ilimaussite-(Ce)} x r_electron= 624.90 barns/cc.

Radioactivity:

GRapi = 20,501.23 (Gamma Ray American Petroleum Institute Units)
Concentration of Ilimaussite-(Ce) per GRapi unit = 48.78 (PPM)

Ilimaussite-(Ce) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

**Estimated Radioactivity from Ilimaussite-(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 / 8.21 cm	465,356	1.26E-05	20,501.23	6.74
100 gm / 3.81 cm	46,536	1.26E-06	2,050.12	0.67
10 gm / 1.77 cm	4,654	1.26E-07	205.01	0.07
1 gm / 8.21 mm	465	1.26E-08	20.50	0.01
0.1 gm / 3.81 mm	47	1.26E-09	2.05	0.00
0.01 gm / 1.77 mm	5	1.26E-10	0.21	0.00
0.001 gm / 0.82 mm	0	1.26E-11	0.02	0.00

Weight of pure Ilimaussite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.45 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

Ilimaussite-(Ce) Classification

Dana Class:

78.07.04.01 (78)Unclassified silicates

(78.07)wholly unclassified silicates

(78.07.04)Dana Group

78.07.04.01 Ilimaussite-(Ce) (Ba,Na)10K3Na4.5Ce5(Nb,Ti)6[Si12O36][Si9O18(O,OH)24]O6 R 32 3

78.07.04.02 Diversilite-(Ce)! Na2(Ba,K)6Ce2FeTi3Si12O36(OH)3(OH,H2O)9 R 32 3

Strunz Class:

09.CB.15 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CB -[Si3O9]6- 3-membered single rings, with insular complex anions

09.CB.15 Ilimaussite-(Ce) (Ba,Na)10K3Na4.5Ce5(Nb,Ti)6[Si12O36][Si9O18(O,OH)24]O6 R 32 3

Other Ilimaussite-(Ce) Information

References:

NAME( CanMin, v 42, p 787) PHYS. PROP.(CanMin, 42:787) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Ilimaussite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

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Ilimaussite-(Ce)

(Ba,Na)10K3Na4.5Ce5(Nb,Ti)6[Si12O36][Si9O18(O,OH)24]O6
Dana No: 78.07.04.01 Strunz No: 09.CB.15
Locality:

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