Home » Mineral Directory

Rutile

A lustrous red, reddish-brown, or black mineral, TiO₂, used as a gemstone, as an ore, and in paints and fillers.

Rutile is a common accessory mineral in intermediate to mafic igneous rocks, and in many metamorphic rocks. Commercially important titanium mineral (titanium dioxide, TiO₂). It forms red to reddish brown, hard, brilliant metallic, slender crystals. Rutile has minor uses in porcelain and glass manufacture as a colouring agent and in making some steels and copper alloys. It is also used as a gem, but synthetic rutile is actually superior to natural crystals for gem use; it has fire (flashes of colour) and brilliance (light deflection) like those of diamond. Rutile is mined in Norway and is widespread in the Alps, the southern U.S., Mexico, and elsewhere.

Rutile is titanium dioxide which is naturally occurring in Australia, USA, India and South Africa. Synthetic rutile can be produced from naturally occurring ilmenite which is a complex oxide with iron. Rutile is used in the manufacture of titanium dioxide pigment.
In Australia most rutile is produced from ilmenite as it naturally occurs in accessible high concentrations and in a form which allows the ready extraction of the rutile. These favourable factors have made ilmenite a competitive raw material for Australia's producers reflected in high export activity. Australia supplies about 40 per cent of the world's ilmenite and about 25 per cent of its rutile. Just seven producers around the world control 93 per cent of world production. Keys to identifying rutile are its strong yellowish to reddish brown color, high relief, and extreme birefringence.

Occurrence

Common in embedded crystals in gneiss or schist, in pegmatites, and free-growing in veins of the alpine type. Since it is also a hard, heavy, and common accessory mineral of primary rocks, it occurs in alluvial concentrations of heavy sands.

Large black shiny crystals, more or less equidimensional, are found in a quartzite at Graves Mountain, Georgia, associated with kyanite and lazulite. Beautiful reticulated growths of slender crystals were found in open seams in North Carolina at Hiddenite. Fine oriented growths of flat reddish rutile needles on hematite plates are common among the Swiss "iron roses." Perfect eightlings and rutile replacements of brookite (TiO₂) crystals (paramorphs) are common at Magnet Cove, Arkansas. Slender red-brown hairs of rutile penetrate quartz crystals--by replacement--to form rutilated quartz, also known as flèches d'amour or Venus hairstone. Brazil, Switzerland, and the U.S. (West Hartford, Vermont, and Alexander Co., North Carolina) have produced fine specimens of this growth of rutile and quartz.

[ Close ]