Mineralogy Database

Tomichite Mineral Data

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General Tomichite Information

Help on Chemical  Formula: Chemical Formula: (V,Fe)4Ti3AsO13(OH)
Help on Composition: Composition: Molecular Weight = 647.82 gm
   Titanium  22.17 %  Ti   36.99 % TiO2
   Vanadium  30.67 %  V    45.12 % V2O3
   Iron       0.86 %  Fe    1.23 % Fe2O3
   Arsenic   11.57 %  As   17.74 % As2O5
   Hydrogen   0.16 %  H     1.39 % H2O
   Oxygen    34.58 %  O
            ______        ______ 
            100.00 %      102.47 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: V3+3.9Fe3+0.1Ti3AsO13(OH)
Help on Environment: Environment: In a specimen from a hydrothermal gold deposit.
Help on IMA Status: IMA Status: Approved IMA 1979
Help on Locality: Locality: Kalgoorlie, Western Australia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Stephan A. Tomich (1914-), consulting geologist who discovered the mineral.
Help on Name Pronunciation: Name Pronunciation: Tomichite + Pronunciation Say TOMICHITE
 

Tomichite Image

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  Tomichite

Comments: Section of drill core with a very rare crystal of tomichite to 1mm.
Location: Hemlo Gold mine, Ontario, Canada. Scale: Core size 2.5 cm.
© Tom Loomis / Dakota Matrix

Tomichite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5021:1:0.3521
Help on Cell Dimensions: Cell Dimensions: a = 7.119, b = 14.176, c = 4.992, Z = 2; beta = 105.05° V = 486.51 Den(Calc)= 4.42
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: A2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.662(1), 2.836(0.9), 1.572(0.5),
 

Physical Properties of Tomichite

Help on Cleavage: Cleavage: None
Help on Color: Color: Black.
Help on Density: Density: 4.16
Help on Diaphaneity: Diaphaneity: Opaque
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Resinous
Help on Streak: Streak: black
 

Optical Properties of Tomichite

Help on Optical Data: Optical Data: Biaxial (?)
  NCalc= 2.36 - from Gladstone-Dale relationship (KC = 0.3086) where Ncalc=Dcalc*KC+1
NCalc= 2.28 - from Gladstone-Dale relationship (KC = 0.3086) where Ncalc=Dmeas*KC+1
Help on RL Anisotrophism: RL Anisotrophism: Moderate, yellowish gray to dark gray.
Help on RL Color: RL Color: Gray.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Tomichite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 400 nm   17.90   18.30 
   
 420 nm   17.50   17.90 
 440 nm   17.20   17.60 
 460 nm   17.00   17.50 
 480 nm   17.00   17.50 
 500 nm   16.90   17.50 
 520 nm   17.00   17.60 
 540 nm   17.00   17.70 
 560 nm   17.10   17.80 
 580 nm   17.10   17.90 
 600 nm   17.20   17.90 
 620 nm   17.20   18.00 
 640 nm   17.20   18.00 
 660 nm   17.20   18.00 
 680 nm   17.30   18.00 
 700 nm   17.30   18.00 
Calculated Relative Intensity Colors of Tomichite in Air
Relative
Intensity
   0%   60% 100% 120% 180% 240% 300% 360% 420% 480% 520%
R1                      
R2                      
 

Calculated Properties of Tomichite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.15 gm/cc
note: Specific Gravity of Tomichite =4.42 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PETomichite = 17.94 barns/electron
U=PETomichite x rElectron Density= 74.50 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Tomichite is Not Radioactive
 

Tomichite Classification

Help on  Dana Class: Dana Class: 46.02.03.01 (46)Basic or Halogen-Containing Antimonites, Arsenites and Phosphites
  (46.02)with miscellaneous formulae
  (46.02.03)Derbylite Group
 
46.02.03.01 Tomichite (V,Fe)4Ti3AsO13(OH) A2/m 2/m
 
46.02.03.02 Derbylite (Fe,Fe,Ti)7SbO13(OH) P 21/m 2/m
 
46.02.03.03 Graeserite! (Fe,Ti)4Ti3AsO13(OH) A2/m 2/m
Help on  Strunz Class: Strunz Class: 04.JB.55 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.J - Arsenites, Antimonites, Bismuthites, Sulfites,
  04.JB -Arsenites, antimonites, bismuthites; with additional anions, without H2O
 
04.JB.55 Derbylite (Fe,Fe,Ti)7SbO13(OH) P 21/m 2/m
 
04.JB.55 Graeserite! (Fe,Ti)4Ti3AsO13(OH) A2/m 2/m
 
04.JB.55 Tomichite (V,Fe)4Ti3AsO13(OH) A2/m 2/m
 

Other Tomichite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic3)
Help on See Also: See Also: Links to other databases for Tomichite :
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
15 - WWW-MINCRYST

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

Tomichite

(V,Fe)4Ti3AsO13(OH)
Dana No: 46.02.03.01 Strunz No: 04.JB.55
Locality:

 

Notes:

 

 
   
 


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