Ilmenite

Ilmenite Locality: Ilmen Mts, Chelyabinsk Oblast’, Southern Urals, Urals Region, Russia Dimensions: 4.5 cm x 4.3 cm x 1.5 cm Photo Copyright © Rob Lavinsky & irocks

Chemical Formula: FeTiO
3

Locality: Ilmen Mountains, southern Urals, of the Russia.
Name Origin: Named after It’s locality.

Ilmenite is the titanium-iron oxide mineral with the idealized formula FeTiO
3
. It is a weakly magnetic black or steel-gray solid. From the commercial perspective, ilmenite is the most important ore of titanium.

Structure and properties

Ilmenite crystallizes in the trigonal system. The ilmenite crystal structure consists of an ordered derivative of the corundum structure; in corundum all cations are identical but in ilmenite Fe2+ and Ti4+ ions occupy alternating layers perpendicular to the trigonal c axis. Containing high spin ferrous centers, ilmenite is paramagnetic.

Ilmenite is commonly recognized in altered igneous rocks by the presence of a white alteration product, the pseudo-mineral leucoxene. Often ilmenites are rimmed with leucoxene, which allows ilmenite to be distinguished from magnetite and other iron-titanium oxides. The example shown in the image at right is typical of leucoxene-rimmed ilmenite.

In reflected light it may be distinguished from magnetite by more pronounced reflection pleochroism and a brown-pink tinge.

Samples of ilmenite exhibit a weak response to a hand magnet.

Physical Properties

Cleavage: None
Color: Iron black, Black.
Density: 4.72
Diaphaneity: Opaque
Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Hardness: 5-5.5 – Apatite-Knife Blade
Luminescence: Non-fluorescent.
Luster: Sub Metallic
Magnetism: Naturally weak
Streak: brownish black

Photos :

Ilmenite Arendal, Norway Thumbnail, 2.5 x 2.0 x 1.2 cm © irocks
Ilmenite 6.3×5.7×4.3 cm Bentley Lake, Faraday Mine property Bancroft Ontario, Canada Copyright © David K. Joyce Minerals
Ilmenite Washington, Litchfield Co., Connecticut, USA Cabinet, 12.5 x 8.2 x 7.1 cm © irocks
Ilmenite 3.8×3.0x1.1 cm Bentley Lake, Faraday Mine Property Bancroft Ontario, Canada Copyright © David K. Joyce Minerals
Rutile and Hematite pseudomorph after Ilmenite Mwinilunga  Zambia (05/2007) Specimen size: 6.8 × 4.8 × 2 cm = 2.7” × 1.9” × 0.8” © Fabre Minerals
Spizzicatore Hill, Allumiere, Tolfa Mts District, Rome Province, Latium, Italy © Di Domenico Dario
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