Nacareniobsite-(Ce) Mineral Data

General Nacareniobsite-(Ce) Information

Chemical Formula:

NbNa3Ca3(Ce,La)(Si2O7)2OF3

Composition:

Molecular Weight = 830.67 gm

Sodium 7.20 % Na 9.70 % Na₂O

Calcium 13.99 % Ca 19.58 % CaO

Lanthanum 6.69 % La 7.84 % La₂O₃

Cerium 11.81 % Ce 13.83 % Ce₂O₃

Titanium 1.73 % Ti 2.88 % TiO₂

Niobium 7.83 % Nb 11.20 % Nb₂O₅

Silicon 13.52 % Si 28.93 % SiO₂

Oxygen 28.31 % O

Fluorine 8.92 % F 8.92 % F

- % F -3.76 % -O=F₂

______ ______

100.00 % 99.13 % = TOTAL OXIDE

Empirical Formula:

Nb_0.7Ti_0.3Na_2.6Ca_2.9Ce_0.7La_0.4(Si₂O₇)₂F_3.9O_0.7

Environment:

In groundmass and as a secondary mineral in an arfvedsonite-nepheline syenite.

IMA Status:

Approved IMA 1989

Locality:

Found in the Kvanefjeld tunnel in the Ilimaussaq, intrusion, southern Greenland. Link to MinDat.org Location Data.

Name Origin:

Named for Natrium (sodium), Calcium, Rare Earths, NIOBium, and Silicon in the chemical formula.

Name Pronunciation:

Nacareniobsite-(Ce) + Pronunciation

Nacareniobsite-(Ce) Image

Images:

Nacareniobsite-(Ce)

Comments: White to light brownish nacareniobsite-(Ce) in an igneous rock matrix.
Location: Kvanefjeld Tunnel, IlÃmaussaq massif, Greenland. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Nacareniobsite-(Ce) Crystallography

Axial Ratios:

a:b:c =3.3258:1:1.313

Cell Dimensions:

a = 18.901, b = 5.683, c = 7.462, Z = 2; beta = 101.29° V = 786.02 Den(Calc)= 3.51

Crystal System:

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

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

By Intensity(I/I_o): 3.077(1), 2.031(0.5), 2.955(0.5),

Physical Properties of Nacareniobsite-(Ce)

Cleavage:

{011} Good

Color:

Colorless.

Density:

3.45

Diaphaneity:

Transparent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Lath - Shaped like a small, thin plaster lath, tabular (rectangular) in shape.

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Nacareniobsite-(Ce)

Gladstone-Dale:

CI meas= 0.006 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.023 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1923,KPDmeas= 0.1957,KC= 0.1968
Ncalc = 1.68 - 1.69

Optical Data:

Biaxial (+), a=1.662, b=1.671, g=1.692, bire=0.0300, 2V(Calc)=68, 2V(Meas)=66.

Calculated Properties of Nacareniobsite-(Ce)

Electron Density:

Bulk Density (Electron Density)=3.27 gm/cc
note: Specific Gravity of Nacareniobsite-(Ce) =3.45 gm/cc.

Fermion Index:

Fermion Index = 0.0089367139
Boson Index = 0.9910632861

Photoelectric:

PE_{Nacareniobsite-(Ce)}= 102.24 barns/electron
U=PE_{Nacareniobsite-(Ce)} x r_electron= 334.61 barns/cc.

Radioactivity:

GRapi = 18,715.97 (Gamma Ray American Petroleum Institute Units)
Concentration of Nacareniobsite-(Ce) per GRapi unit = 53.43 (PPM)

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

**Estimated Radioactivity from Nacareniobsite-(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	414,317	1.12E-05	18,715.97	6.15
100 gm / 3.81 cm	41,432	1.12E-06	1,871.60	0.62
10 gm / 1.77 cm	4,143	1.12E-07	187.16	0.06
1 gm / 8.21 mm	414	1.12E-08	18.72	0.01
0.1 gm / 3.81 mm	41	1.12E-09	1.87	0.00
0.01 gm / 1.77 mm	4	1.12E-10	0.19	0.00
0.001 gm / 0.82 mm	0	1.12E-11	0.02	0.00

Weight of pure Nacareniobsite-(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
Estimated Thorium Activity ( 0.92 % Th) From Sum REE Elements (18.50 % REE)

Nacareniobsite-(Ce) Classification

Dana Class:

56.02.05.02 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O

(56.02)with cations in [4] and/or >[4] coordination

(56.02.05)Mosandrite and related species

56.02.05.01 Mosandrite Na(Na,Ca)2(Ca,Ce,Y)4(Ti,Nb,Zr)(Si2O7)2(O,F)2F3 P 2₁ 2

56.02.05.02 Nacareniobsite-(Ce) NbNa3Ca3(Ce,La)(Si2O7)2OF3 P 2₁/a 2/m

56.02.05.03 Fersmanite Ca4(Na,Ca)4(Ti,Nb)4(Si2O7)2O8F3 C 2/c 2/m

56.02.05.04 Gotzenite (Ca,Na)3(Ti,Al)Si2O7(F,OH)2 P1 1

56.02.05.05 Rinkite! Na(Na,Ca)2(Ca,Ce)4(Ti,Nb)(Si2O7)2(O,F)2 P 2₁ 2

56.02.05.06 IMA2008-024! (Ca,Na,REE,[])7(Nb,Ti)[Si2O7]2OF3 Cc m

56.02.05.07 Dovyrenite! Ca6Zr[Si2O7]2(OH)4 Pnnm 2/m 2/m 2/m

Strunz Class:

09.BE.20 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BE -Si2O7 groups with additional anions;

09.BE.20 Nacareniobsite-(Ce) NbNa3Ca3(Ce,La)(Si2O7)2OF3 P 2₁/a 2/m

09.BE.20 Mosandrite Na(Na,Ca)2(Ca,Ce,Y)4(Ti,Nb,Zr)(Si2O7)2(O,F)2F3 P 2₁ 2

09.BE.20 Rinkite! Na(Na,Ca)2(Ca,Ce)4(Ti,Nb)(Si2O7)2(O,F)2 P 2₁ 2

09.BE.20 IMA2008-024! (Ca,Na,REE,[])7(Nb,Ti)[Si2O7]2OF3 Cc m

Other Nacareniobsite-(Ce) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Am.Min.,Vol.75,p708,1990) OPTIC PROP.(Am.Min.,Vol.75,p708,1990)

See Also:

Links to other databases for Nacareniobsite-(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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Nacareniobsite-(Ce)

NbNa3Ca3(Ce,La)(Si2O7)2OF3
Dana No: 56.02.05.02 Strunz No: 09.BE.20
Locality:

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