Allanite-(Y) Mineral Data

General Allanite-(Y) Information

Chemical Formula:

(Y,Ce,Ca)2(Al,Fe+++)3(SiO4)3(OH)

Composition:

Molecular Weight = 598.63 gm

Calcium 2.01 % Ca 2.81 % CaO

Cerium 14.04 % Ce 16.45 % Ce₂O₃

Yttrium 17.82 % Y 22.63 % Y₂O₃

Aluminum 10.14 % Al 19.16 % Al₂O₃

Iron 7.00 % Fe 10.00 % Fe₂O₃

Silicon 14.07 % Si 30.11 % SiO₂

Hydrogen 0.17 % H 1.50 % H₂O

Oxygen 34.74 % O

______ ______

100.00 % 102.67 % = TOTAL OXIDE

Empirical Formula:

Y_1.2Ce_0.6Ca_0.3Al_2.25Fe³⁺_0.75(SiO₄)₃(OH)

IMA Status:

Valid Species (Pre-IMA) 1949 - Dana Number Modified from 58.2.1a.3

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named after the Scottish mineralogist, T. Allan (1777-1833).

Name Pronunciation:

Allanite-(Y)

Synonym:

Orthite

Allanite-(Y) Image

Images:

Allanite-(Y)

Comments: Dark brown allanite-(Y) in matrix.
Location: Boden, Marienberg District, Erzgebirge, Saxony, Germany. Scale: Picture size 10 mm.
© Thomas Witzke / Abraxas-Verlag

Allanite-(Y) Crystallography

Axial Ratios:

a:b:c =1.5617:1:1.7791

Cell Dimensions:

a = 8.98, b = 5.75, c = 10.23, Z = 2; beta = 115° V = 478.74 Den(Calc)= 4.15

Crystal System:

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

Physical Properties of Allanite-(Y)

Cleavage:

{001} Imperfect, {100} Imperfect

Color:

Brown, Black.

Density:

3.3 - 4.2, Average = 3.75

Diaphaneity:

Translucent to opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Disseminated - Occurs in small, distinct particles dispersed in matrix.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

5.5 - Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Greasy

Streak:

grayish brown

Optical Properties of Allanite-(Y)

Gladstone-Dale:

CI meas= 0.014 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.109 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1845,KPDmeas= 0.2042,KC= 0.207
Ncalc = 1.68 - 1.87

Optical Data:

Biaxial (-), a=1.715-1.791, b=1.718-1.815, g=1.733-1.822, bire=0.0180-0.0310, 2V(Calc)=50-56, 2V(Meas)=40-80. Dispersion distinct to strong, r > v.

Pleochroism (x):

colorless, pale yellow, yellowish brown, pink, or greenish yellow.

Pleochroism (y):

yellowish brown, reddish brown, brownish green, dark reddish brown, or greenish brown.

Pleochroism (z):

pale yellow, brownish yellow, brownish green, green, or brown.

Calculated Properties of Allanite-(Y)

Electron Density:

Bulk Density (Electron Density)=3.55 gm/cc
note: Specific Gravity of Allanite-(Y) =3.75 gm/cc.

Fermion Index:

Fermion Index = 0.0082504498
Boson Index = 0.9917495502

Photoelectric:

PE_Allanite-(Y)= 93.85 barns/electron
U=PE_Allanite-(Y) x r_electron= 333.18 barns/cc.

Radioactivity:

GRapi = 14,180.81 (Gamma Ray American Petroleum Institute Units)
Concentration of Allanite-(Y) per GRapi unit = 70.52 (PPM)

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

**Estimated Radioactivity from Allanite-(Y)** - 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 / 7.99 cm	314,576	8.50E-06	14,180.81	4.66
100 gm / 3.71 cm	31,458	8.50E-07	1,418.08	0.47
10 gm / 1.72 cm	3,146	8.50E-08	141.81	0.05
1 gm / 7.99 mm	315	8.50E-09	14.18	0.00
0.1 gm / 3.71 mm	31	8.50E-10	1.42	0.00
0.01 gm / 1.72 mm	3	8.50E-11	0.14	0.00
0.001 gm / 0.80 mm	0	8.50E-12	0.01	0.00

Weight of pure Allanite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.75 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 ( 0.70 % Th) From Sum REE Elements (14.04 % REE)

Allanite-(Y) Classification

Dana Class:

58.02.01c.03 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups

(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2)

(58.02.01c)Epidote group (Allanite subgroup)

58.02.01c.01 Allanite-(Ce) (Ce,Ca,Y)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

58.02.01c.02 Allanite-(La)! Ca(REE,Ca)Al2(Fe,Fe)(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01c.03 Allanite-(Y) (Y,Ce,Ca)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

58.02.01c.04 Dissakisite-(Ce) Ca(Ce,REE)(Mg,Fe)(Al,Fe)2Si3O12(OH) P 2₁/m 2/m

58.02.01c.05 Dissakisite-(La)! (Ca,Fe,Th,La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F)withLa>Ce P 2₁/m 2/m

58.02.01c.06 Manganiandrosite-(La)! (Mn,Ca)(La,Ce,Ca,Nd)AlMnMn(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01c.07 Ferriallanite-(Ce)! CaCe(Fe,Fe,Al)3[SiO4][Si2O7]O(OH) P 2₁/m 2/m

58.02.01c.08 Vastmanlandite-(Ce)! (Ce,La)3CaAl2Mg2[Si2O7][SiO4]3F(OH)2 P 2₁/m 2/m

58.02.01c.09 Manganiandrosite-(Ce)! (Mn,Ca)(Ce,REE)AlMnMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

58.02.01c.10 Vanadoandrosite-(Ce)! (Mn,Ca)(REE)VAlMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

Strunz Class:

09.BG.05b 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups;

09.BG.05b Allanite-(La)! Ca(REE,Ca)Al2(Fe,Fe)(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

09.BG.05b Allanite-(Y) (Y,Ce,Ca)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

09.BG.05b Allanite-(Ce) (Ce,Ca,Y)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

09.BG.05b Manganiandrosite-(La)! (Mn,Ca)(La,Ce,Ca,Nd)AlMnMn(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

09.BG.05b Dissakisite-(Ce) Ca(Ce,REE)(Mg,Fe)(Al,Fe)2Si3O12(OH) P 2₁/m 2/m

09.BG.05b Manganiandrosite-(Ce)! (Mn,Ca)(Ce,REE)AlMnMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

09.BG.05b Vanadoandrosite-(Ce)! (Mn,Ca)(REE)VAlMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

09.BG.05b Dissakisite-(La)! (Ca,Fe,Th,La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F)withLa>Ce P 2₁/m 2/m

09.BG.05b Ferriallanite-(Ce)! CaCe(Fe,Fe,Al)3[SiO4][Si2O7]O(OH) P 2₁/m 2/m

09.BG.05b Uedaite-(Ce)! MnCeAl2Fe(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

Other Allanite-(Y) Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Mason68) OPTIC PROP.(Heinrich65)

See Also:

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

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Allanite-(Y)

(Y,Ce,Ca)2(Al,Fe+++)3(SiO4)3(OH)
Dana No: 58.02.01c.03 Strunz No: 09.BG.05b
Locality:

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