Franklinite Mineral Data

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General Franklinite Information

Chemical Formula:

(Zn,Mn++,Fe++)(Fe+++,Mn+++)2O4

Composition:

Molecular Weight = 236.54 gm

Manganese 18.58 % Mn 9.00 % MnO / 16.69 % Mn₂O₃

Zinc 16.59 % Zn 20.65 % ZnO

Iron 37.78 % Fe 3.04 % FeO / 50.63 % Fe₂O₃

Oxygen 27.06 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Zn_0.6Mn²⁺_0.3Fe²⁺_0.1Fe³⁺_1.5Mn³⁺_0.5O₄

Environment:

Zinc rich orebody weathered and later metamorphosed..

IMA Status:

Valid Species (Pre-IMA) 1819

Locality:

Dominant ore mineral at Franklin and Sterling Hill, New Jersey, USA. Link to MinDat.org Location Data.

Name Origin:

Named after its locality which was named after Benjamin Franklin (1706-1790), American scientist and inventor.

Name Pronunciation:

Franklinite + Pronunciation

Synonym:

ICSD 81205

PDF 22-1012

Franklinite Image

Images:

Franklinite

Comments: Black, octahedral franklinite crystals to 1.4 cm across on white calcite.
Location: Franklin, Sussex County, New Jersey, USA. Scale: 2.9 x 2 cm.
© John Veevaert

Images:

Franklinite Esperite Hardystonite

Comments: Pale brown porcelaneous esperite with pinkish gray hardystonite and black franklinite.
Location: Franklin, Sussex County, New Jersey. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Franklinite Rinmanite

Comments: B&W image (reflected light) of a polished section of rinmanite and franklinite (white) with associated silicates.
Location: Garpenberg Norra Zn-Pb mine, Hedemora, Dalarna, in south-central Sweden. (CanMin, v39:1675). Scale: Scale Bar 0.2 mm.
© Canadian Mineralogist

Franklinite Crystallography

Cell Dimensions:

a = 8.42, Z = 8; V = 596.95 Den(Calc)= 5.26

Crystal System:

Isometric - HexoctahedralH-M Symbol (4/m 3 2/m) Space Group: F d3m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.55(1), 1.499(0.8), 2.99(0.7),

Forms:

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Forms: ( 1 1 1) ( 1 0 0)

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Crystal Structure:

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Pavese A , Levy D , Hoser A , American Mineralogist , 85 (2000) p.1497-1502, Cation distribution in synthetic zinc ferrite (Zn0.97Fe2.02O4) from, in situ high temperature neutron powder diffraction, Sample at T = 300 K

View Additional jPOWD Structure files for Franklinite
[1] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [2] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [3] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [4] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [5] [50] [51] [6] [7] [8] [9]

Physical Properties of Franklinite

Cleavage:

None

Color:

Black, Brownish black.

Density:

5.07 - 5.22, Average = 5.14

Diaphaneity:

Opaque

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luminescence:

Non-fluorescent.

Luster:

Sub Metallic

Magnetism:

Naturally weak

Streak:

reddish brown

Optical Properties of Franklinite

Gladstone-Dale:

CI meas= 0.005 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.027 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2586,KPDmeas= 0.2643,KC= 0.2658
Ncalc = 2.35 - 2.4

Optical Data:

Isotropic, n=2.36.

RL Color:

White to gray, with dark red internal reflections.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Franklinite in Air**
λ	R	∑ R(λ)
400 nm	19.20
420 nm	19.20
440 nm	19.20
460 nm	19.20
480 nm	19.20
500 nm	19.10
520 nm	19.00
540 nm	18.60
560 nm	18.20
580 nm	17.80
600 nm	17.40
620 nm	17.10
640 nm	16.80
660 nm	16.60
680 nm	16.40
700 nm	16.30

**Calculated Relative Intensity Colors of Franklinite in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	510%
R

Calculated Properties of Franklinite

Electron Density:

Bulk Density (Electron Density)=4.85 gm/cc
note: Specific Gravity of Franklinite =5.15 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Franklinite= 24.90 barns/electron
U=PE_Franklinite x rElectron Density= 120.91 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Franklinite is Not Radioactive

Franklinite Classification

Dana Class:

07.02.02.04 (07)Multiple Oxides

(07.02)(A+ B++)2 X4 Spinel group

(07.02.02)(Iron subgroup)

07.02.02.01 Magnesioferrite MgFe2O4 F d3m 4/m 3 2/m

07.02.02.02 Jacobsite (Mn,Fe,Mg)(Fe,Mn)2O4 F d3m 4/m 3 2/m

07.02.02.03 Magnetite FeFe2O4 F d3m 4/m 3 2/m

07.02.02.04 Franklinite (Zn,Mn,Fe)(Fe,Mn)2O4 F d3m 4/m 3 2/m

07.02.02.05 Trevorite NiFe2O4 F d3m 4/m 3 2/m

07.02.02.06 Cuprospinel (Cu,Mg)Fe2O4 F d3m 4/m 3 2/m

07.02.02.07 Brunogeierite (Ge,Fe)Fe2O4 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 Franklinite Information

References:

NAME( Mason68) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

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

Franklinite

(Zn,Mn++,Fe++)(Fe+++,Mn+++)2O4
Dana No: 07.02.02.04 Strunz No: 04.BB.05
Locality:

Notes: