Irtyshite Mineral Data

General Irtyshite Information

Chemical Formula:

Na2(Ta,Nb)4O11

Composition:

Molecular Weight = 901.74 gm

Sodium 5.10 % Na 6.87 % Na₂O

Tantalum 70.23 % Ta 85.76 % Ta₂O₅

Niobium 5.15 % Nb 7.37 % Nb₂O₅

Oxygen 19.52 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Ta_3.5Nb_0.5O₁₁

Environment:

Granitic pegmatites.

IMA Status:

Approved IMA 1985

Locality:

Irtysh River area, eastern Kazakhstan. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Irtyshite + Pronunciation

Synonym:

ICSD 201714

PDF 38-391

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Irtyshite Crystallography

Axial Ratios:

a:c = 1:5.90113

Cell Dimensions:

a = 6.231, c = 36.77, Z = 6; V = 1,236.35 Den(Calc)= 7.27

Crystal System:

Hexagonal - DipyramidalH-M Symbol (6/m) Space Group: P 6₃/m

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

By Intensity(I/I_o): 3.029(1), 2.78(0.9), 3.082(0.9),

Physical Properties of Irtyshite

Cleavage:

None

Color:

Colorless.

Density:

7.03

Diaphaneity:

Transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

7 - Quartz

Luster:

Adamantine

Streak:

white

Optical Properties of Irtyshite

Optical Data:

Uniaxial (?).

NCalc= 2.18 - from Gladstone-Dale relationship (KC = 0.1623) where Ncalc=Dcalc*KC+1
NCalc= 2.14 - from Gladstone-Dale relationship (KC = 0.1623) where Ncalc=Dmeas*KC+1

RL Anisotrophism:

Noted.

RL Bireflectance:

Noted.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Irtyshite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
486 nm	18.00	19.00
553 nm	18.60	19.50
589 nm	18.90	19.60
656 nm	18.50	18.70

**Calculated Relative Intensity Colors of Irtyshite in Air**
Relative Intensity	0%	50%	100%	150%	200%	250%	300%	350%	400%	450%	490%
R₁
R₂

Calculated Properties of Irtyshite

Electron Density:

Bulk Density (Electron Density)=6.22 gm/cc
note: Specific Gravity of Irtyshite =7.27 gm/cc.

Fermion Index:

Fermion Index = 0.0001779607
Boson Index = 0.9998220393

Photoelectric:

PE_Irtyshite= 853.38 barns/electron
U=PE_Irtyshite x rElectron Density=5,311.44 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Irtyshite is Not Radioactive

Irtyshite Classification

Dana Class:

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

(08.06)Dana Type

(08.06.02)Calciotantite Group

08.06.02.01 Calciotantite Ca(Ta,Nb)4O11 P 6₃22 6 2 2

08.06.02.02 Natrotantite Na2Ta4O11 R 3-c 3 2/m

08.06.02.03 Irtyshite Na2(Ta,Nb)4O11 P 6₃/m 6/m

Strunz Class:

04.DJ.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DJ -With large (± medium-sized) cations; polyhedral frameworks

04.DJ.05 Calciotantite Ca(Ta,Nb)4O11 P 6₃22 6 2 2

04.DJ.05 Irtyshite Na2(Ta,Nb)4O11 P 6₃/m 6/m

04.DJ.05 Natrotantite Na2Ta4O11 R 3-c 3 2/m

Other Irtyshite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Irtyshite :
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 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Print or Cut-and-Paste your Irtyshite Specimen Label here :

Irtyshite

Na2(Ta,Nb)4O11
Dana No: 08.06.02.03 Strunz No: 04.DJ.05
Locality:

Notes: