Geikielite Mineral Data

General Geikielite Information

Chemical Formula:

MgTiO3

Composition:

Molecular Weight = 120.18 gm

Magnesium 20.22 % Mg 33.54 % MgO

Titanium 39.84 % Ti 66.46 % TiO₂

Oxygen 39.94 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

MgTiO₃

Environment:

Forms during contact metamorphism of impure magnesian limestones. Also in carbonatites, kimberlites, and serpentinized ultramafic rocks. Forms a series with ilmenite.

IMA Status:

Valid Species (Pre-IMA) 1892

Locality:

Gem gravels of the Rakwana and Balanoda districts, Sri Lanka. Link to MinDat.org Location Data.

Name Origin:

Named for Sir Archibald Geikie (1835-1924), Scottish geologist and Director-General of the Geological Survey of Great Brition.

Name Pronunciation:

Geikielite + Pronunciation

Synonym:

ICSD 65794

PDF 6-494

Geikielite Image

Images:

Geikielite

Comments: Black, lustrous crystals of geikielite in matrix.
Location: Monte dei tre Abati, Coli, Piacenza Province, Emilia-Romagna, Italy. Scale: Picture size 2.2 mm.
© Thomas Witzke / Abraxas-Verlag

Geikielite Crystallography

Axial Ratios:

a:c = 1:2.77093

Cell Dimensions:

a = 5.086, c = 14.093, Z = 6; V = 315.71 Den(Calc)= 3.79

Crystal System:

Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: R 3

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

By Intensity(I/I_o): 2.722(1), 2.218(0.7), 2.527(0.55),

Physical Properties of Geikielite

Cleavage:

{1011} Distinct

Color:

Bluish black, Brownish black.

Density:

Diaphaneity:

Translucent to opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

6 - Orthoclase

Luster:

Sub Metallic

Streak:

purple brown

Optical Properties of Geikielite

Dichroism (e):

brownish red or purplish red.

Dichroism (w):

pinkish red or pinkish red.

Gladstone-Dale:

CI meas= 0.126 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.078 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.3028,KPDmeas= 0.2869,KC= 0.3283
Ncalc = 2.24 - 2.31

Optical Data:

Uniaxial (-), e=1.95-1.98, w=2.31-2.35, bire=0.3600-0.3700.

RL Anisotrophism:

Strong, purplish red.

RL Color:

Gray with red internal reflections.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Geikielite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	17.70	13.90
420 nm	17.20	13.50
440 nm	16.80	13.10
460 nm	16.40	12.80
480 nm	16.10	12.40
500 nm	15.80	12.20
520 nm	15.50	12.00
540 nm	15.40	11.80
560 nm	15.30	11.80
580 nm	15.20	11.80
600 nm	15.20	11.70
620 nm	15.20	11.80
640 nm	15.30	11.80
660 nm	15.30	11.80
680 nm	15.40	11.80
700 nm	15.40	11.80

**Calculated Relative Intensity Colors of Geikielite in Air**
Relative Intensity	0%	80%	100%	160%	240%	320%	400%	480%	560%	640%	720%	740%
R₁
R₂

Calculated Properties of Geikielite

Electron Density:

Bulk Density (Electron Density)=3.66 gm/cc
note: Specific Gravity of Geikielite =3.79 gm/cc.

Fermion Index:

Fermion Index = 0.07
Boson Index = 0.93

Photoelectric:

PE_Geikielite= 7.03 barns/electron
U=PE_Geikielite x rElectron Density= 25.73 barns/cc.

Radioactivity:

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

Geikielite Classification

Dana Class:

04.03.05.02 (04)Simple Oxides

(04.03)with a cation charge of 3+ (A+++2 O3)

(04.03.05)Ilmenite Group

04.03.05.01 Ilmenite FeTiO3 R 3 3

04.03.05.02 Geikielite MgTiO3 R 3 3

04.03.05.03 Pyrophanite MnTiO3 R 3 3

04.03.05.04 Ecandrewsite (Zn,Fe,Mn)TiO3 R 3 3

04.03.05.05 Melanostibite Mn(Sb,Fe)O3 R 3 3

04.03.05.06 Brizziite-III NaSbO3 R 3 3

04.03.05.07 Akimotoite! (Mg,Fe)SiO3 R 3 3

Strunz Class:

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

04.C - Metal:Oxygen = 2:3, 3:5, and Similar

04.CB -With medium-sized cations

04.CB.05 Auroantimonate* AuSbO3 Ortho ? Ortho

04.CB.05 Geikielite MgTiO3 R 3 3

04.CB.05 Brizziite-III NaSbO3 R 3 3

04.CB.05 Brizziite-VII NaSbO3 R 3 3

04.CB.05 Ecandrewsite (Zn,Fe,Mn)TiO3 R 3 3

04.CB.05 Corundum Al2O3 R 3c 3 2/m

04.CB.05 Eskolaite Cr2O3 R 3c 3 2/m

04.CB.05 Hematite Fe2O3 R 3c 3 2/m

04.CB.05 Karelianite V2O3 R 3c 3 2/m

04.CB.05 Ilmenite FeTiO3 R 3 3

04.CB.05 Melanostibite Mn(Sb,Fe)O3 R 3 3

04.CB.05 Pyrophanite MnTiO3 R 3 3

04.CB.05 Romanite* (Fe,U,Pb)2(Ti,Fe)O4 Trig ? Trig

04.CB.05 Tistarite! Ti2O3 R 3c 3 2/m

Other Geikielite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Geikielite :
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 Geikielite Specimen Label here :

Geikielite

MgTiO3
Dana No: 04.03.05.02 Strunz No: 04.CB.05
Locality:

Notes:

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