General Allanite-(Y) Information Chemical Formula: |
(Y,Ce,Ca)2(Al,Fe+++)3(SiO4)3(OH) |
Composition: |
Molecular Weight = 598.63 gm |
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Calcium 2.01 % Ca 2.81 % CaO |
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Cerium 14.04 % Ce 16.45 % Ce2O3 |
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Yttrium 17.82 % Y 22.63 % Y2O3 |
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Aluminum 10.14 % Al 19.16 % Al2O3 |
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Iron 7.00 % Fe 10.00 % Fe2O3 |
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Silicon 14.07 % Si 30.11 % SiO2 |
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Hydrogen 0.17 % H 1.50 % H2O |
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Oxygen 34.74 % O |
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100.00 % 102.67 % = TOTAL OXIDE |
Empirical Formula: |
Y1.2Ce0.6Ca0.3Al2.25Fe3+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:
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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 - PrismaticH-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: |
PEAllanite-(Y) = 93.85 barns/electron |
U=PEAllanite-(Y) x relectron= 333.18 barns/cc. Radioactivity: |
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GRapi = 14,180.81 (Gamma Ray American Petroleum Institute Units)
Allanite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.
Weight of pure Allanite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.75 gm/cc.* | Allanite-(Y) Classification Dana Class: |
58.02.01c.03 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups |
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(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2) |
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(58.02.01c)Epidote group (Allanite subgroup) |
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Strunz Class: |
09.BG.05b 09 - SILICATES (Germanates) |
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09.B - Sorosilicates |
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09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups; |
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| 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 Search for Allanite-(Y) using: Visit our Advertisers for Allanite-(Y) : A Bijoux Google Search for Allanite-(Y)Adam's Minerals Google Search for Allanite-(Y) Cape Minerals Google Search for Allanite-(Y) Dakota Matrix Minerals Google Search for Allanite-(Y) Excalibur Mineral Corp. Google Search for Allanite-(Y) Exceptional Minerals Google Search for Allanite-(Y) John Betts Fine Minerals Search for Allanite-(Y) McDougall Minerals Google Search for Allanite-(Y) Mineral News Website Link Rock and Mineral Shows Google Search for Allanite-(Y) Weinrich Minerals, Inc. Google Search for Allanite-(Y) Ask about Allanite-(Y) here : Print or Cut-and-Paste your Allanite-(Y) Specimen Label here :
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