Mineralogy Database

Foordite Mineral Data

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General Foordite Information

Help on Chemical  Formula: Chemical Formula: Sn++(Nb,Ta)2O6
Help on Composition: Composition: Molecular Weight = 444.54 gm
   Tantalum  20.35 %  Ta   24.85 % Ta2O5
   Niobium   31.35 %  Nb   44.85 % Nb2O5
   Tin       26.70 %  Sn   30.30 % SnO
   Oxygen    21.59 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: SnNb1.5Ta0.5O6
Help on Environment: Environment: Alluvial pebble originating from a highly differentiated granite pegmatite, formed under reducing conditions deficient in Fe, Mn, Na, Ca, and F
Help on IMA Status: IMA Status: Approved IMA 1988
Help on Locality: Locality: 15 km north-northwest of Lutsiro, near the Sebeya River, western Rwanda. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Eugene Edward Foord (1946-1998), American mineralogist with the U.S. Geological Survey, Denver, Colorado, USA, student of granite pegmatites.
Help on Name Pronunciation: Name Pronunciation: Foordite Say FOORDITE
Help on Synonym: Synonym: ICSD 202827
  PDF 45-1350

Foordite Image

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Comments: Brownish massive foordite.
Location: Manono, Shaba (Katanga), Congo (Zaïre). Scale: Picture size 7 mm.
© Thomas Witzke / Abraxas-Verlag

Foordite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =3.5042:1:1.1399
Help on Cell Dimensions: Cell Dimensions: a = 17.097, b = 4.879, c = 5.562, Z = 4; beta = 90.85° V = 463.91 Den(Calc)= 6.36
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.849(1), 3.071(0.5), 3.1(0.5),

Physical Properties of Foordite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Brownish yellow.
Help on Density: Density: 6.734
Help on Diaphaneity: Diaphaneity: Translucent
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Vitreous - Adamantine
Help on Streak: Streak: yellow white

Optical Properties of Foordite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.04 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2035,KPDmeas= 0.1922,KC= 0.2001
Ncalc = 2.27 - 2.35
Help on Optical Data: Optical Data: Biaxial (+), b=2.294

Calculated Properties of Foordite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.61 gm/cc
note: Specific Gravity of Foordite =6.36 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.04
Boson Index = 0.96
Help on Photoelectric: Photoelectric: PEFoordite = 371.30 barns/electron
U=PEFoordite x rElectron Density=2,082.39 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Foordite is Not Radioactive

Foordite Classification

Help on  Dana Class: Dana Class: (08)Multiple Oxides with Nb, Ta, and Ti
  (08.03)where A (B2O6)
  (08.03.10)Dana Group Thoreaulite SnTa2O6 C 2/c 2/m Foordite Sn(Nb,Ta)2O6 C 2/c 2/m
Help on  Strunz Class: Strunz Class: 04.DG.15 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.D - Metal:Oxygen = 1:2 and similar
  04.DG -With large (� medium-sized) cations; chains of edge-sharing octahedra
04.DG.15 Foordite Sn(Nb,Ta)2O6 C 2/c 2/m
04.DG.15 Thoreaulite SnTa2O6 C 2/c 2/m

Other Foordite Information

Help on References: References: NAME( AntBidBlaNic3) PHYS. PROP.(Am.Min.,Vol.75,p707,1990) OPTIC PROP.(Am.Min.,Vol.75,p707,1990)
Help on See Also: See Also: Links to other databases for Foordite :
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 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Dana No: Strunz No: 04.DG.15





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