Euxenite-(Y) Mineral Data

General Euxenite-(Y) Information

Chemical Formula:

(Y,Ca,Ce)(Nb,Ta,Ti)2O6

Composition:

Molecular Weight = 392.28 gm

Calcium 2.04 % Ca 2.86 % CaO

Cerium 3.57 % Ce 4.18 % Ce₂O₃

Yttrium 15.86 % Y 20.15 % Y₂O₃

Tantalum 18.45 % Ta 22.53 % Ta₂O₅

Titanium 2.44 % Ti 4.07 % TiO₂

Niobium 33.16 % Nb 47.43 % Nb₂O₅

Oxygen 24.47 % O

______ ______

100.00 % 101.22 % = TOTAL OXIDE

Empirical Formula:

Y_0.7Ca_0.2Ce_0.12(Ta_0.2)2(Nb_0.7)2(Ti_0.1)O₆

Environment:

Granite pegmatites and a component of detrital black sands.

IMA Status:

Valid Species (Pre-IMA) 1870

Locality:

Jolster, Sondfjord, Norway. Link to MinDat.org Location Data.

Name Origin:

From the Greek for "friendly to strangers, hospitable," in allusion to the rare elements that it contains.

Name Pronunciation:

Euxenite-(Y)

Synonym:

ICSD 100175

Lyndochite

PDF 14-463

Euxenite-(Y) Image

Images:

Euxenite-(Y)

Comments: Crystal of euxenite-(Y) in matrix.
Location: Trout Creek Pass, Chaffee County, Colorado, USA. Scale: Crystal size 1.5 cm.
© John Veevaert

Euxenite-(Y) Crystallography

Axial Ratios:

a:b:c =0.3788:1:0.3545

Cell Dimensions:

a = 5.52, b = 14.57, c = 5.166, Z = 3; V = 415.48 Den(Calc)= 4.70

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcan

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

By Intensity(I/I_o): 2.99(1), 2.95(0.4), 3.66(0.4),

Physical Properties of Euxenite-(Y)

Cleavage:

None

Color:

Brownish black, Brown, Yellow, Olive green.

Density:

4.7 - 5, Average = 4.84

Diaphaneity:

Translucent to opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

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

Hardness:

6.5 - Pyrite

Luminescence:

Non-fluorescent.

Luster:

Greasy (Oily)

Streak:

reddish brown

Optical Properties of Euxenite-(Y)

Gladstone-Dale:

CI meas= -0.061 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.095 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2447,KPDmeas= 0.2371,KC= 0.2234
Ncalc = 2.05 - 2.12

Optical Data:

Isotropic, n=2.06-2.24.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Euxenite-(Y) in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	13.70	15.60
546 nm	13.00	15.60
589 nm	12.50	15.00
650 nm	12.40	15.00

**Calculated Relative Intensity Colors of Euxenite-(Y) in Air**
Relative Intensity	0%	70%	100%	140%	210%	280%	350%	420%	490%	560%	630%	700%
R₁
R₂

Calculated Properties of Euxenite-(Y)

Electron Density:

Bulk Density (Electron Density)=4.35 gm/cc
note: Specific Gravity of Euxenite-(Y) =4.85 gm/cc.

Fermion Index:

Fermion Index = 0.0033235343
Boson Index = 0.9966764657

Photoelectric:

PE_Euxenite-(Y)= 303.63 barns/electron
U=PE_Euxenite-(Y) x r_electron=1,322.15 barns/cc.

Radioactivity:

GRapi = 3,420.62 (Gamma Ray American Petroleum Institute Units)
Concentration of Euxenite-(Y) per GRapi unit = 292.34 (PPM)

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

**Estimated Radioactivity from Euxenite-(Y)** - mild
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 / 7.33 cm	80,008	2.16E-06	3,420.62	1.12
100 gm / 3.40 cm	8,001	2.16E-07	342.06	0.11
10 gm / 1.58 cm	800	2.16E-08	34.21	0.01
1 gm / 7.33 mm	80	2.16E-09	3.42	0.00
0.1 gm / 3.40 mm	8	2.16E-10	0.34	0.00
0.01 gm / 1.58 mm	1	2.16E-11	0.03	0.00
0.001 gm / 0.73 mm	0	2.16E-12	0.00	0.00

Weight of pure Euxenite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.85 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 ( 0.18 % Th) From Sum REE Elements ( 3.57 % REE)

Euxenite-(Y) Classification

Dana Class:

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

(08.03)where A (B2O6)

(08.03.08)Polycrase Group

08.03.08.01 Polycrase-(Y) (Y,Ca,Ce,U,Th)(Ti,Nb,Ta)2O6 Pcan 2/m 2/m 2/m

08.03.08.02 Euxenite-(Y) (Y,Ca,Ce)(Nb,Ta,Ti)2O6 Pcan 2/m 2/m 2/m

08.03.08.03 Tanteuxenite-(Y) (Y,Ce,Ca)(Ta,Nb,Ti)2(O,OH)6 Pcan 2/m 2/m 2/m

08.03.08.04 Yttrocrasite-(Y) (Y,Th,Ca,U)(Ti,Fe)2(O,OH)6 Unk Ortho

08.03.08.05 Uranopolycrase (U,Y)(Ti,Nb,Ta)2O6 P bcn 2/m 2/m 2/m

Strunz Class:

04.DG.05 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 (ï¿½ medium-sized) cations; chains of edge-sharing octahedra

04.DG.05 Fersmite (Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6 Pcan 2/m 2/m 2/m

04.DG.05 Euxenite-(Y) (Y,Ca,Ce)(Nb,Ta,Ti)2O6 Pcan 2/m 2/m 2/m

04.DG.05 Kobeite-(Y) (Y,U)(Ti,Nb)2(O,OH)6(?) Cubic Cubic

04.DG.05 Loranskite-(Y) (Y,Ce,Ca)ZrTaO6(?) Unk Ortho

04.DG.05 Polycrase-(Y) (Y,Ca,Ce,U,Th)(Ti,Nb,Ta)2O6 Pcan 2/m 2/m 2/m

04.DG.05 Tanteuxenite-(Y) (Y,Ce,Ca)(Ta,Nb,Ti)2(O,OH)6 Pcan 2/m 2/m 2/m

04.DG.05 Uranopolycrase (U,Y)(Ti,Nb,Ta)2O6 P bcn 2/m 2/m 2/m

04.DG.05 Yttrocrasite-(Y) (Y,Th,Ca,U)(Ti,Fe)2(O,OH)6 Unk Ortho

Other Euxenite-(Y) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Euxenite-(Y) :
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
13 - WWW-MINCRYST

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Print or Cut-and-Paste your Euxenite-(Y) Specimen Label here :

Euxenite-(Y)

(Y,Ca,Ce)(Nb,Ta,Ti)2O6
Dana No: 08.03.08.02 Strunz No: 04.DG.05
Locality:

Notes:

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