Ominelite Mineral Data

General Ominelite Information

Chemical Formula:

(Fe++,Mg)Al3BSiO9

Composition:

Molecular Weight = 316.53 gm

Magnesium 0.77 % Mg 1.27 % MgO

Aluminum 25.57 % Al 48.32 % Al₂O₃

Iron 15.88 % Fe 20.43 % FeO

Silicon 8.87 % Si 18.98 % SiO₂

Boron 3.42 % B 11.00 % B₂O₃

Oxygen 45.49 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺_0.9Mg_0.1Al₃BSiO₉

Environment:

Accessory mineral found in a high alumina porphyritic granite of Miocene age associated with sekaninaite (Fe cordierite). Fe 2+ -analogue of grandidierite.

IMA Status:

Approved IMA 2002 (Dana # Added)

Locality:

Omine Mountains near the misen River at Tenkawa, Yoshio, Nara Prefecture, Japan. Link to MinDat.org Location Data.

Name Origin:

Named after the locality.

Synonym:

IMA1999-025

Ominelite Image

Images:

Ominelite

Comments: Photomicrograph of thin-section (plain light) of zoned ominelite (omn) with quartz (qtz) and plagioclase (pl) in alkali feldspar. (AmMin 87:163).
Location: Misen River in Tenkawa, Yoshino, Nara Prefecture, Japan. Scale: Grain size 0.6 mm.
© American Mineralogist

Ominelite Crystallography

Axial Ratios:

a:b:c =0.9311:1:0.5183

Cell Dimensions:

a = 10.363, b = 11.129, c = 5.769, Z = 4; V = 665.34 Den(Calc)= 3.16

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbnm

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

By Intensity(I/I_o): 5.05(1), 5.21(0.9)(200), 2.18(0.75)(150,421,312),2.79(0.75)(040), 2.97(0.75)(101), 2.9(0.5), 3.51(0.5)(130), 3.73(0.5)(121), 5.57(0.5)(020),

Physical Properties of Ominelite

Cleavage:

None

Color:

Blue.

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Equant Grains - Granular material with equel dimensions in x, y, and z.

Hardness:

7 - Quartz

Luster:

Vitreous (Glassy)

Streak:

pale blue

Optical Properties of Ominelite

Gladstone-Dale:

CI calc= -0.003 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2047,KC= 0.2041
Ncalc = 1.64

Optical Data:

Biaxial (-), a=1.631, b=1.654, g=1.656, bire=0.0250, 2V(Calc)=32, 2V(Meas)=31.5. Dispersion strong, r >> v.

Calculated Properties of Ominelite

Electron Density:

Bulk Density (Electron Density)=3.09 gm/cc
note: Specific Gravity of Ominelite =3.16 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Ominelite= 5.87 barns/electron
U=PE_Ominelite x rElectron Density= 18.12 barns/cc.

Radioactivity:

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

Ominelite Classification

Dana Class:

54.01.01.02 (54)Nesosilicate Borosilicates and Some Beryllosilicates

(54.01)with (BO3)

(54.01.01)Grandidierite Group

54.01.01.01 Grandidierite (Mg,Fe)Al3(BO4)(SiO4)O Pbnm 2/m 2/m 2/m

54.01.01.02 Ominelite! (Fe,Mg)Al3BSiO9 Pbnm 2/m 2/m 2/m

Strunz Class:

09.AJ.05 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AJ -Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra,

09.AJ.05 Grandidierite (Mg,Fe)Al3(BO4)(SiO4)O Pbnm 2/m 2/m 2/m

09.AJ.05 Ominelite! (Fe,Mg)Al3BSiO9 Pbnm 2/m 2/m 2/m

Other Ominelite Information

References:

NAME( AmMin, Vol 87, p 160) PHYS. PROP.(AmMin, Vol 87, p 160) OPTIC PROP.(AmMin, Vol 87, p 160)

See Also:

Links to other databases for Ominelite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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

Ominelite

(Fe++,Mg)Al3BSiO9
Dana No: 54.01.01.02 Strunz No: 09.AJ.05
Locality:

Notes:

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