Formanite-(Y) Mineral Data

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General Formanite-(Y) Information

Chemical Formula:

YTaO4

Composition:

Molecular Weight = 333.85 gm

Yttrium 26.63 % Y 33.82 % Y₂O₃

Tantalum 54.20 % Ta 66.18 % Ta₂O₅

Oxygen 19.17 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

YTaO₄

IMA Status:

Valid Species (Pre-IMA) 1944

Locality:

Coolegong, New South Wales, Australia Link to MinDat.org Location Data.

Name Origin:

Named for Francis Gloster Forman (1904-1980), government geologist.

Name Pronunciation:

Formanite-(Y) + Pronunciation

Synonym:

ICSD 36076

PDF 26-1478

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Formanite-(Y) Crystallography

Axial Ratios:

a:c = 1:1.47225

Cell Dimensions:

a = 7.75, c = 11.41, Z = 9; V = 685.31 Den(Calc)= 7.28

Crystal System:

Tetragonal - DipyramidalH-M Symbol (4/m) Space Group: I 4₁/a

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

By Intensity(I/I_o): 3.13(1), 2.93(0.9), 1.57(0.7),1.64(0.7), 1.9(0.7), 1.19(0.6), 1.22(0.6), 2.72(0.6),

Crystal Structure:

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Wolten G M , Acta Crystallographica , 23 (1967) p.939-944, The structure of the M -phase of YTaO4, a third fergusonite polymorph, Locality: synthetic

Physical Properties of Formanite-(Y)

Cleavage:

{111} Indistinct

Color:

Brownish black, Black.

Density:

7.03

Diaphaneity:

Subtranslucent to Opaque

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

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

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

5.5-6.5 - Knife Blade-Pyrite

Luster:

Vitreous - Metallic

Streak:

brown

Optical Properties of Formanite-(Y)

Gladstone-Dale:

CI meas= -0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.023 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1538,KPDmeas= 0.1593,KC= 0.1574
Ncalc = 2.11 - 2.15

Optical Data:

Isotropic, n=2.05-2.19.

Calculated Properties of Formanite-(Y)

Electron Density:

Bulk Density (Electron Density)=6.06 gm/cc
note: Specific Gravity of Formanite-(Y) =7.03 gm/cc.

Fermion Index:

Fermion Index = 0.0001570537
Boson Index = 0.9998429463

Photoelectric:

PE_{Formanite-(Y)}= 683.22 barns/electron
U=PE_{Formanite-(Y)} x rElectron Density=4,143.37 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Formanite-(Y) is Not Radioactive

Formanite-(Y) Classification

Dana Class:

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

(08.01)where A BO4

(08.01.01)Fergusonite Group (Tetragonal)

08.01.01.01 Fergusonite-(Y) YNbO4 I 4₁/a 4/m

08.01.01.02 Formanite-(Y) YTaO4 I 4₁/a 4/m

08.01.01.03 Fergusonite-(Ce)* (Ce,La,Y)NbO4 I 4₁/a 4/m

08.01.01.04 Fergusonite-(Nd)* (Nd,Ce)(Nb,Ti)O4 I 4₁/a 4/m

Strunz Class:

07.GA.10 07 - SULFATES (SELENATES, TELLURATES)

07.G - Molybdates, Wolframates and Niobates

07.GA -Without additional anions or H2O

07.GA.10 Formanite-(Y) YTaO4 I 4₁/a 4/m

07.GA.10 Iwashiroite-(Y)! YTaO4 P 2/a 2/m

Other Formanite-(Y) Information

References:

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

See Also:

Links to other databases for Formanite-(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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Print or Cut-and-Paste your Formanite-(Y) Specimen Label here :

Formanite-(Y)

YTaO4
Dana No: 08.01.01.02 Strunz No: 07.GA.10
Locality:

Notes: