Ilmenite

Ilmenite is an oxide mineral recognized among collectors for its crystal form and distribution, with several world-class Chinese localities.

IMA Abbreviation (Whitney-Evans 2010)
Ilm
→ Ilmenite
Fe-Ti oxide
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
Pseudomorph Relationships
Replaced by — this mineral commonly becomes:
Rutile replacement
Ilmenite (FeTiO₃) weathers/exsolves to rutile (TiO₂) — important Ti ore process.
Heavy mineral sands.
A pseudomorph (Greek "false form") is a mineral with the external shape of another species — the chemistry has changed but the crystal habit is inherited.
Magnetism
Category:
weakly paramagnetic
Test result:
Slight pull from rare-earth magnet
FeTiO₃; useful for separating from magnetite during sluicing.
Test with rare-earth magnet (N42 or N52 neodymium). Suspend specimen on thread for sensitive paramagnetic detection. Diamagnetic minerals are weakly repelled (visible only with strong magnets like bismuth).
Streak Test
black / brown-black
Distinguishes from magnetite (true black streak) — slightly browner.
Streak = color of the powdered mineral. Drag specimen across unglazed white porcelain plate (Mohs 6.5). For minerals harder than the plate, crush a small flake into powder and observe color.
Mohs 5–6
Vickers (~) 540 HV
Knoop (~) 620 HK
Geological setting
Plutonic igneousKimberlitePlacer
Diagnostic properties
Trace magnetism
Element composition by mass

Formula: FeTiO₃ · molar mass: 151.71 g/mol

Fe 36.81%
O 31.64%
Ti 31.55%

Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.

Mohs Hardness 5–6
1
Talc
2
Gypsum
3
Calcite
4
Fluorite
5
Apatite
6
Orthoclase
7
Quartz
8
Topaz
9
Corundum
10
Diamond

Ilmenite sits at 5–6 on the Mohs scale — just hard enough to scratch glass.

Colors:
Streak
Black to brown
Crystal system
Trigonal
Oxides & HydroxidesOxides
TL;DR · 1 min read
Ilmenite (FeTiO₃) is the iron-titanium oxide and the principal ore of titanium for paint pigments (TiO₂ "titanium white"). It forms in mafic igneous rocks (gabbros, anorthosites), as detrital placer beach sands (Australia, India), and as a kimberlite indicator mineral.

Ilmenite (FeTiO₃) is the iron-titanium oxide and the principal ore of titanium for paint pigments (TiO₂ “titanium white”). It forms in mafic igneous rocks (gabbros, anorthosites), as detrital placer beach sands (Australia, India), and as a kimberlite indicator mineral. Panzhihua (Sichuan) hosts massive layered ilmenite-magnetite ore.

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