Mineralogy Database

Yttrialite-(Y) Mineral Data

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General Yttrialite-(Y) Information

Help on Chemical  Formula: Chemical Formula: (Y,Th)2Si2O7
Help on Composition: Composition: Molecular Weight = 417.54 gm
   Yttrium  31.94 %  Y    40.56 % Y2O3
   Thorium  27.79 %  Th   31.62 % ThO2
   Silicon  13.45 %  Si   28.78 % SiO2
   Oxygen   26.82 %  O
           ______        ______ 
           100.00 %      100.96 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Y1.5Th0.5Si2O7
Help on Environment: Environment: A late-stage mineral in some rare-earth-bearing pegmatites. Associated with gadolinite.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1889
Help on Locality: Locality: Baringer Hill pegmatite, 26 km west of Burnet, and from Rode Ranch, near Blu�ton, Llano County, Texas, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the yttrium in its composition.
Help on Name Pronunciation: Name Pronunciation: Yttrialite-(Y) + Pronunciation Say YTTRIALITE-(Y)
Help on Synonym: Synonym: ICSD 28004
  PDF 24-1427

Yttrialite-(Y) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9106:1:0.6228
Help on Cell Dimensions: Cell Dimensions: a = 7.34, b = 8.06, c = 5.02, Z = 2; beta = 108.5° V = 281.64 Den(Calc)= 4.92
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/m

Physical Properties of Yttrialite-(Y)

Help on Cleavage: Cleavage: None
Help on Color: Color: Green, Orangish yellow.
Help on Density: Density: 4.58
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Massive - Uniformly indistinguishable crystals forming large masses.
Help on Hardness: Hardness: 5-5.5 - Apatite-Knife Blade
Help on Luminescence: Luminescence: Non-fluorescent.

Optical Properties of Yttrialite-(Y)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.089 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.152 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1541,KPDmeas= 0.1655,KC= 0.1816
Ncalc = 1.83 - 1.89
Help on Optical Data: Optical Data: Isotropic, n=1.758.

Calculated Properties of Yttrialite-(Y)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.11 gm/cc
note: Specific Gravity of Yttrialite-(Y) =4.58 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0064114338
Boson Index = 0.9935885662
Help on Photoelectric: Photoelectric: PEYttrialite-(Y) = 693.08 barns/electron
U=PEYttrialite-(Y) x relectron=2,850.86 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 532,369.91 (Gamma Ray American Petroleum Institute Units)
Concentration of Yttrialite-(Y) per GRapi unit =1,878.39 (PPB)

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

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 57.13 ± 14.28 grams of pure Yttrialite-(Y) .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 5713.4 ±1428.4 grams of pure Yttrialite-(Y) .

Estimated Radioactivity from Yttrialite-(Y) - strong
Curies (Ci)
If Held in Hand
For One Hour
1000 gm / 7.47 cm 12,448,139 3.36E-04 532,369.91 175.03
100 gm / 3.47 cm 1,244,814 3.36E-05 53,236.99 17.50
10 gm / 1.61 cm 124,481 3.36E-06 5,323.70 1.75
1 gm / 7.47 mm 12,448 3.36E-07 532.37 0.18
0.1 gm / 3.47 mm 1,245 3.36E-08 53.24 0.02
0.01 gm / 1.61 mm 124 3.36E-09 5.32 0.00
0.001 gm / 0.75 mm 12 3.36E-10 0.53 0.00

Weight of pure Yttrialite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.58 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

Yttrialite-(Y) Classification

Help on  Dana Class: Dana Class: 55.02.01b.03 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions
  (55.02)with cations in [6] coordination
  (55.02.01b)Thortveitite related species
55.02.01b.01 Rowlandite-(Y) Y4FeSi4O14F2(?) None
55.02.01b.02 Thalenite-(Y) Y3Si3O10(OH) P 21/n 2/m
55.02.01b.03 Yttrialite-(Y) (Y,Th)2Si2O7 P 21/m 2/m
55.02.01b.04 Fluorthalenite-(Y)! Y3Si3O10F P 21/m 2/m
Help on  Strunz Class: Strunz Class: 09.BC.05 09 - SILICATES (Germanates)
  09.B - Sorosilicates
  09.BC -Si2O7 groups, without non-tetrahedral anions;
09.BC.05 Keiviite-(Y) (Y,Yb)2Si2O7 C 2/m 2/m
09.BC.05 Gittinsite CaZrSi2O7 C 2/m 2/m
09.BC.05 Keiviite-(Yb) (Yb,Y)2Si2O7 C 2/m 2/m
09.BC.05 Thortveitite (Sc,Y)2Si2O7 C 2/m 2/m
09.BC.05 Yttrialite-(Y) (Y,Th)2Si2O7 P 21/m 2/m

Other Yttrialite-(Y) Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Yttrialite-(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

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Dana No: 55.02.01b.03 Strunz No: 09.BC.05





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