Mineralogy Database

Simpsonite Mineral Data

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General Simpsonite Information

Help on Chemical  Formula: Chemical Formula: Al4(Ta,Nb)3O13(OH)
Help on Composition: Composition: Molecular Weight = 813.65 gm
   Tantalum  53.37 %  Ta   65.17 % Ta2O5
   Niobium    5.71 %  Nb    8.17 % Nb2O5
   Aluminum  13.26 %  Al   25.06 % Al2O3
   Hydrogen   0.12 %  H     1.11 % H2O
   Oxygen    27.53 %  O
            ______        ______ 
            100.00 %       99.51 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Al4Ta2.4Nb0.5O13(OH)
Help on Environment: Environment: Accessory mineral in some tantalum-rich granite pegmatites.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1938
Help on Locality: Locality: Tabba Tabba, Western Australia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Edward Sydney Simpson (1875-1939), Western Australian government mineralogis and mineral analyst.
Help on Name Pronunciation: Name Pronunciation: Simpsonite + Pronunciation Say SIMPSONITE
Help on Synonym: Synonym: ICSD 67673
  PDF 15-705

Simpsonite Image

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Comments: Translucent pale pink simpsonite crystal fragment.
Location: Alto do Giz, Equidor, Rio Grande do Sol, Brazil. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Simpsonite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.6119
Help on Cell Dimensions: Cell Dimensions: a = 7.377, c = 4.514, Z = 1; V = 212.74 Den(Calc)= 6.35
Help on Crystal System: Crystal System: Trigonal - Pyramidal H-M Symbol (3) Space Group: P 3
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 1.64(1), 1.39(0.95), 2.84(0.85),

Physical Properties of Simpsonite

Help on Cleavage: Cleavage: None
Help on Color: Color: Brownish yellow, Colorless, White, Light brown, Light yellow.
Help on Density: Density: 6.7
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Striated - Parallel lines on crystal surface or cleavage face.
Help on Hardness: Hardness: 7-7.5 - Quartz-Garnet
Help on Luminescence: Luminescence: Fluorescent, Short UV=blue white, yellowish blue pale yellow, Long UV=blue white, yellowish blue pale yellow.
Help on Luster: Luster: Vitreous - Adamantine
Help on Streak: Streak: white

Optical Properties of Simpsonite

Help on Dichroism (e): Dichroism (e): colorless.
Help on Dichroism (w): Dichroism (w): colorless.
Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.122 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.074 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.163,KPDmeas= 0.1545,KC= 0.1759
Ncalc = 2.12 - 2.18
Help on Optical Data: Optical Data: Uniaxial (-), e=2.025, w=2.045, bire=0.0200.

Calculated Properties of Simpsonite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=5.63 gm/cc
note: Specific Gravity of Simpsonite =6.35 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0001963736
Boson Index = 0.9998036264
Help on Photoelectric: Photoelectric: PESimpsonite = 629.45 barns/electron
U=PESimpsonite x rElectron Density=3,543.83 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Simpsonite is Not Radioactive

Simpsonite Classification

Help on  Dana Class: Dana Class: (08)Multiple Oxides with Nb, Ta, and Ti
  (08.07)Dana Type
  (08.07.05)Dana Group Simpsonite Al4(Ta,Nb)3O13(OH) P 3 3
Help on  Strunz Class: Strunz Class: 04.DC.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.D - Metal:Oxygen = 1:2 and similar
  04.DC -With medium-sized cations; sheets of edge-sharing octahedra
04.DC.10 Simpsonite Al4(Ta,Nb)3O13(OH) P 3 3

Other Simpsonite Information

Help on References: References: NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)
Help on See Also: See Also: Links to other databases for Simpsonite :
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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Dana No: Strunz No: 04.DC.10





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