Irtyshite Mineral Data +

B & L Fine Minerals

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:	Na2Ta3.5Nb0.5O11
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.
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
X Ray Diffraction:	By Intensity(I/Io): 3.029(1), 2.78(0.9), 3.082(0.9),
Physical Properties of Irtyshite
Cleavage:	None
Color:	Colorless.
Density:	7.03
Diaphaniety:	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:	relectron=6.22 gm/cc note: rIrtyshite =7.27 gm/cc.
Fermion Index	Fermion Index = 0.00017 Boson Index = 0.99983
Photoelectric:	PEIrtyshite = 853.38 barns/electron U=PEIrtyshite x relectron=5,311.44 barns/cc.
Radioactivity:	GRapi = 0 (Gamma Ray American Petroleum Institute Units) Irtyshite is Not Radioactive
Irtyshite Classification
Dana Class:	8.6.2.3 (8)Multiple Oxides with Nb, Ta, and Ti
	(8.6)Dana Type
	(8.6.2)Dana Group
	8.6.2.1 Calciotantite Ca(Ta,Nb)4O11 P 6322 6 2 2
	8.6.2.2 Natrotantite Na2Ta4O11 R 3-c 3 2/m
	8.6.2.3 Irtyshite Na2(Ta,Nb)4O11 P 63/m 6/m
Strunz Class:	IV/D.26-30 IV - Oxides
	IV/D - Oxides with metal : oxygen = 1:2 (MO2 and related compounds)
	IV/D.26 - Lithiotantite - Cesplumtantite series
	IV/D.26-10 Lithiotantite Li(Ta,Nb)3O8 P 21/c 2/m
	IV/D.26-20 Natrotantite Na2Ta4O11 R 3-c 3 2/m
	IV/D.26-30 Irtyshite Na2(Ta,Nb)4O11 P 63/m 6/m
	IV/D.26-40 Calciotantite Ca(Ta,Nb)4O11 P 6322 6 2 2
	IV/D.26-50 Ungursaite? NaCa5(Ta,Nb)24O65(OH) P 63/m,P 63 Hex
	IV/D.26-60 Cesplumtantite (Cs,Na,Ca)2(Pb,Sb,Sn)3Ta8O24 Unk Tetra
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 -Google Images 5 -Google Scholar 6 -Handbook of Mineralogy (UofA) 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas 12 -École des Mines de Paris Search for Irtyshite using:   Web webmineral.com [ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO] Visit our Advertisers for Irtyshite : AA Mineral Specimens B & L Fine Minerals Crystal Vaults Dan Weinrich Fine Minerals Dan Weinrich Auctions e-Rocks Auctions Excalibur Minerals Exceptional Minerals Fabre Minerals Greenside Minerals Heliodor John Betts Fine Minerals Mason's Minerals Mineral News Mineral of the Month Club MineralsWeb Fine Minerals Rockshop.cz T G Fine Minerals Wrights Rock Shop Translate Irtyshite Mineral Data : Ask about Irtyshite here : Ask-A-Mineralogist from the Mineralogical Society of America Mindat.org's Discussion Groups Original Rockhounds Discussion Group Rockhounds Discussion Group on Yahoo Groups Mineral Discussion Forum from Fabre Minerals - also available in Español Print or Cut-and-Paste your Irtyshite Specimen Label here : Irtyshite Na2(Ta,Nb)4O11 Dana No: 8.6.2.3 Strunz No: IV/D.26-30 Locality:   Notes: