Mineralogy Database

Carmichaelite Mineral Data

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General Carmichaelite Information

Help on Chemical  Formula: Chemical Formula: (Ti,Cr,Fe)[O2-x(OH)x],x~0.5
Help on Composition: Composition: Molecular Weight = 76.54 gm
   Titanium  38.79 %  Ti   64.71 % TiO2
   Chromium  12.91 %  Cr   16.88 % CrO
   Iron       5.84 %  Fe    7.51 % FeO
   Hydrogen   0.66 %  H     5.88 % H2O
   Oxygen    41.81 %  O
            ______        ______ 
            100.00 %       94.98 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ti0.62Cr0.19Fe2+0.08O1.5(OH)0.5
Help on Environment: Environment: Microscopic inclusions in mantle-derived pyrope crystals. The mineral is inferred to have co-precipitated with the pyrope host in the presence of a fluid or melt phase at 650-750 de g C and 20-25 kbar pressures.
Help on IMA Status: IMA Status: Approved IMA 1996 (Dana # Added)
Help on Locality: Locality: Garnet Ridge, an ultramafic diatreme on the Colorado Plateau in Arizona, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Ian S. E. Charmchael, Professor of Geology at the University of California, Berkeley, in recognition
Help on Synonym: Synonym: ICSD 89831

Carmichaelite Image

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Comments: Backscattered electron (BSE) image of a grain of carmichaelite included in pyrope in GRPy-40. (AmMin 85:794).
Location: Garnet Ridge, an ultramafic diatreme on the Colorado Plateau in Arizona.. Scale: See Image.
© American Mineralogist

Carmichaelite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.6905:1:4.4286
Help on Cell Dimensions: Cell Dimensions: a = 7.706, b = 4.5583, c = 20.187, Z = 22; beta = 92.334° V = 708.51 Den(Calc)= 3.95
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.842(1)(115), 3.773(0.94)(013), 2.664(0.7)(213),1.688(0.54)(322), 1.661(0.44)(128), 1.679(0.44)(226), 1.648(0.34)(1.1.11),

Physical Properties of Carmichaelite

Help on Cleavage: Cleavage: None
Help on Color: Color: Cinnamon brown, Black.
Help on Diaphaneity: Diaphaneity: Opaque to translucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Inclusions - Generally found as inclusions in other minerals.
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Metallic

Optical Properties of Carmichaelite

Help on Gladstone-Dale: Gladstone-Dale: CI calc= -0.138 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.3671,KC= 0.3225
Ncalc = 2.27
Help on Optical Data: Optical Data: Biaxial (?), b=2-2.9

Calculated Properties of Carmichaelite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.80 gm/cc
note: Specific Gravity of Carmichaelite =3.95 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.06
Boson Index = 0.94
Help on Photoelectric: Photoelectric: PECarmichaelite = 11.14 barns/electron
U=PECarmichaelite x rElectron Density= 42.30 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Carmichaelite is Not Radioactive

Carmichaelite Classification

Help on  Dana Class: Dana Class: (08)Multiple Oxides with Nb, Ta, and Ti
  (08.07)Dana Type
  (08.07.13)Dana Group Carmichaelite! (Ti,Cr,Fe)[O2-x(OH)x],x~0.5 P 21/c 2/m
Help on  Strunz Class: Strunz Class: 04.DB.50 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.D - Metal:Oxygen = 1:2 and similar
  04.DB -With medium-sized cations; chains of edge-sharing octahedra
04.DB.50 Carmichaelite! (Ti,Cr,Fe)[O2-x(OH)x],x~0.5 P 21/c 2/m

Other Carmichaelite Information

Help on References: References: NAME( AmMin, Vol 85, p 792) PHYS. PROP.(AmMin, Vol 85, p 792) OPTIC PROP.(AmMin, Vol 85, p 792)
Help on See Also: See Also: Links to other databases for Carmichaelite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

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Dana No: Strunz No: 04.DB.50





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