Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

Chromite Mineral Data Search Webmineral :

[Minerals] [Gems] [Sale Items] [Gold Rings] [Big Stuff] [Main Page]

Shop early for Holiday Season and get the best stuff. You can put it on layaway for up to six weeks!

General Chromite Information

Chemical Formula: Fe++Cr2O4 Composition: Molecular Weight = 223.84 gm

Chromium 46.46 % Cr 67.90 % Cr2O3 Iron 24.95 % Fe 32.10 % FeO

Oxygen 28.59 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula: Fe2+Cr2O4 Environment: Cummulate mineral found in ultramafic portions of layered mafic

intrusions. Common in meteorites. IMA Status: Valid Species (Pre-IMA) 1845 Locality: Bastide de la Carrade, Gassin, Var, France. Link to MinDat.org Location

Data. Name Origin: Named after its chemical composition. Synonym: Chrome iron ore

Chromic iron Ferrichromite - magnetic, altered ICSD 20819 PDF 34-140

Chromite Image

Images:Chromite Antigorite

Comments: Chromite veins in yellow to green antigoritewith picrolite, chromian antigorite and dolomite (polishedsection).Location: Wood's Mine, near 'Texas', Little BritainTownship, Lancaster County, Pennsylvania, USA. Scale:See Photo.© Jeff Weissman / Photographic Guide to Mineral Species

Images:Chromite Theophrastite

Comments: Green pearly scaly theophrastite coatings onmassive dark chromite.Location: Vermion Region, near Thessaloniki, KedrikiMakedhonia, Greece. Scale: See Photo.

Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images News Help About

Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

© Jeff Weissman / Photographic Guide to Mineral Species

Chromite Crystallography

Cell Dimensions: a = 8.36, Z = 8; V = 584.28 Den(Calc)= 5.09 Crystal System: Isometric - HexoctahedralH-M Symbol (4/m 3 2/m) Space Group: F

d3m X Ray Diffraction: By Intensity(I/Io): 2.52(1), 1.46(0.9), 1.6(0.9), Forms:

MouseDbl Clk - Start-Stop RotationRMB - Cycle Display ModesDrag1 - Manipulate CrystalDrag2 - ResizeKeyboardS - StereoI - Indicies<space> - Start-Stop RotationF - Fit to ScreenM - MenuHelp on Above

Forms: ( 1 1 1)

Warning: this large pop-up is very compute intensive and may not workwell with some computers.

Crystal Structure:

Mousedrag1 - LMB Manipulate Structuredrag2 - RMB Resize/RotateKeyboardS - Stereo Pair on/offH - Help ScreenI - Data InfoA - Atoms On/OffP - Polyhedra On/OffB - Bonds On/OffHelp on Above

Lenaz D , Princivalle F , The Canadian Mineralogist , 43 (2005) p.1305-1314, Thecrystal chemistry of detrital chromian spinel from the, southeastern Alps and OuterDinarides: The discrimination of, supplies from areas of similar tectonic setting?,Sample: CL 1

View Additional jPOWD Structure files for Chromite[1] [10] [2] [3] [4] [5] [6] [7] [8] [9]

Physical Properties of Chromite

Cleavage: None Color: Black, Brownish black. Density: 4.5 - 5.09, Average = 4.79 Diaphaneity: Opaque Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix. Habit: Massive - Granular - Common texture observed in granite and other

igneous rock. Habit: Nuggets - Irregular lumps produced by stream transport of malleable

metals. Hardness: 5.5 - Knife Blade Luminescence: Non-fluorescent. Luster: Metallic Magnetism: Naturally weak Streak: brown

Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

Optical Properties of Chromite

Gladstone-Dale: CI meas= 0.092 (Poor) - where the CI = (1-KPDmeas/KC)CI calc= 0.145 (Poor) - where the CI = (1-KPDcalc/KC)KPDcalc= 0.22,KPDmeas= 0.2336,KC= 0.2573Ncalc = 2.16 - 2.31

Optical Data: Isotropic, n=2.08-2.16. RL Color: Gray-white with a brownish tint and brownish red internal reflections. RL Pleochroism: None. Reflectivity Standardized Intensity (100%)

Reflection Spectra of Chromite inAir

λ R ∑ R(λ)

400 nm 13.20

420 nm 13.10 440 nm 13.00 460 nm 12.80 480 nm 12.60 500 nm 12.40 520 nm 12.20 540 nm 12.00 560 nm 11.90 580 nm 11.80 600 nm 11.70 620 nm 11.70 640 nm 11.60 660 nm 11.60 680 nm 11.60 700 nm 11.60

Calculated Relative Intensity Colors of Chromite in AirRelativeIntensity 0% 80% 100% 160% 240% 320% 400% 480% 560% 640% 720% 740%

R

Calculated Properties of Chromite

Electron Density: Bulk Density (Electron Density)=4.54 gm/ccnote: Specific Gravity of Chromite =4.80 gm/cc.

Fermion Index: Fermion Index = 0.04Boson Index = 0.96

Photoelectric: PEChromite = 18.28 barns/electronU=PEChromite x rElectron Density= 83.03 barns/cc.

Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)Chromite is Not Radioactive

Chromite Classification

Dana Class: 07.02.03.03 (07)Multiple Oxides (07.02)(A+ B++)2 X4 Spinel group (07.02.03)(Chromium subgroup)

Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

07.02.03.01 Magnesiochromite MgCr2O4 F d3m 4/m 3 2/m

07.02.03.02 Manganochromite (Mn,Fe)(Cr,V)2O4 F d3m 4/m 3 2/m

07.02.03.03 Chromite FeCr2O4 F d3m 4/m 3 2/m

07.02.03.04 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 F d3m 4/m 3 2/m

07.02.03.05 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 F d3m 4/m 3 2/m

07.02.03.06 Zincochromite ZnCr2O4 F d3m 4/m 3 2/m

Strunz Class: 04.BB.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites,antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.B - Metal:Oxygen = 3:4 and similar 04.BB -With only medium-sized cations 04.BB.05 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 F d3m 4/m 3 2/m

04.BB.05 Filipstadite (Mn,Mg)4SbFeO8 pseudo ISO 2/m 2/m 2/m

04.BB.05 Magnetite FeFe2O4 F d3m 4/m 3 2/m

04.BB.05 Gahnite ZnAl2O4 F d3m 4/m 3 2/m

04.BB.05 Chromite FeCr2O4 F d3m 4/m 3 2/m

04.BB.05 Galaxite (Mn,Mg)(Al,Fe)2O4 F d3m 4/m 3 2/m

04.BB.05 Cuprospinel (Cu,Mg)Fe2O4 F d3m 4/m 3 2/m

04.BB.05 Donathite? (Fe,Mg)(Cr,Fe)2O4 P 4/nnm 4/m 2/m 2/m

04.BB.05 Brunogeierite (Ge,Fe)Fe2O4 F d3m 4/m 3 2/m

04.BB.05 Coulsonite FeV2O4 F d3m 4/m 3 2/m

04.BB.05 Hercynite FeAl2O4 F d3m 4/m 3 2/m

04.BB.05 Franklinite (Zn,Mn,Fe)(Fe,Mn)2O4 F d3m 4/m 3 2/m

04.BB.05 Jacobsite (Mn,Fe,Mg)(Fe,Mn)2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesiochromite MgCr2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesioferrite MgFe2O4 F d3m 4/m 3 2/m

04.BB.05 Magnesiocoulsonite MgV2O4 F d3m 4/m 3 2/m

04.BB.05 Manganochromite (Mn,Fe)(Cr,V)2O4 F d3m 4/m 3 2/m

04.BB.05 Qandilite (Mg,Fe)2(Ti,Fe,Al)O4 F d3m 4/m 3 2/m

04.BB.05 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 F d3m 4/m 3 2/m

04.BB.05 Spinel MgAl2O4 F d3m 4/m 3 2/m

04.BB.05 Ulvospinel TiFe2O4 F d3m 4/m 3 2/m

04.BB.05 Zincochromite ZnCr2O4 F d3m 4/m 3 2/m

04.BB.05 Trevorite NiFe2O4 F d3m 4/m 3 2/m

04.BB.05 Vuorelainenite (Mn,Fe)(V,Cr)2O4 F d3m 4/m 3 2/m

Other Chromite Information

References: NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)OPTIC PROP.(AntBidBlaNic1)

See Also: Links to other databases for Chromite :1 - Am. Min. Crystal Structure Database2 - Amethyst Galleries' Mineral Gallery3 - Athena4 - EUROmin Project5 - Ecole des Mines de Paris6 - Glendale Community College7 - Google Images8 - Google Scholar9 - Handbook of Mineralogy (MinSocAm)10 - HyperPhysics11 - MinDAT12 - MinMax(Deutsch)13 - MinMax(English)14 - Mineral and Gemstone Kingdom15 - Mineralienatlas (Deutsch)

Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

16 - Philatelic Mineralogy17 - QUT Mineral Atlas18 - Ruff.Info19 - Scandinavian mineral gallery20 - University of Colorado - Mineral Structure Data21 - WWW-MINCRYST

Search for Chromite using:

Web webmineral.com

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA][MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Chromite :

B & L Fine MineralsCrystalarium.comDan Weinrich Fine MineralsDan Weinrich Auctionse-Rocks AuctionsExcalibur MineralsExceptional MineralsFabre MineralsJohn Betts Fine MineralsLapis Mineral JournalMineral NewsMineral of the Month ClubWrights Rock Shop

Translate Chromite Mineral Data :

Ask about Chromite here :Ask-A-Mineralogist from the Mineralogical Society of AmericaMindat.org's Discussion GroupsOriginal Rockhounds Discussion GroupRockhounds Discussion Group on Yahoo GroupsMineral Discussion Forum from Fabre Minerals - also available in Español

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

Chromite

Fe++Cr2O4 Dana No: 07.02.03.03 Strunz No: 04.BB.05

Chromite Mineral Data

http://webmineral.com/data/Chromite.shtml[1/12/2011 11:17:22 PM]

Locality:

Notes: