Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Habit:
Striated - Parallel lines on crystal surface or cleavage face.
Hardness:
6 - Orthoclase
Luminescence:
Non-fluorescent.
Luster:
Sub Metallic
Streak:
blackish brown
Optical Properties of Columbite-(Fe)
Gladstone-Dale:
CI meas= 0.149 (Poor) - where the CI = (1-KPDmeas/KC) CI calc= 0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.25,KPDmeas= 0.2135,KC= 0.251 Ncalc = 2.33 - 2.83
Optical Data:
Biaxial (+), b=2.29-2.4
RL Color:
Grayish white with a brownish tint and reddish internal reflections.
Reflectivity
Standardized Intensity (100%) Reflection Spectra of Columbite-(Fe) in Air
λ
R1
R2
∑ R1(λ)
∑ R2(λ)
400 nm
18.40
19.10
420 nm
17.70
18.60
440 nm
17.30
18.20
460 nm
17.10
17.90
480 nm
16.90
17.70
500 nm
16.90
17.60
520 nm
16.80
17.50
540 nm
16.80
17.40
560 nm
16.70
17.30
580 nm
16.70
17.20
600 nm
16.70
17.20
620 nm
16.60
17.10
640 nm
16.50
17.10
660 nm
16.40
16.90
680 nm
16.30
16.80
700 nm
16.10
16.80
Calculated Relative Intensity Colors of Columbite-(Fe) in Air
Relative Intensity
0%
60%
100%
120%
180%
240%
300%
360%
420%
480%
530%
R1
R2
Calculated Properties of Columbite-(Fe)
Electron Density:
Bulk Density (Electron Density)=4.97 gm/cc note: Specific Gravity of Columbite-(Fe) =5.38 gm/cc.
Fermion Index:
Fermion Index = 0.0036428616 Boson Index = 0.9963571384
Photoelectric:
PEColumbite-(Fe) = 89.38 barns/electron U=PEColumbite-(Fe) x rElectron Density= 444.33 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Columbite-(Fe) is Not Radioactive
Columbite-(Fe) Classification
Dana Class:
08.03.02.02(08)Multiple Oxides with Nb, Ta, and Ti
Chemical Formula: 
