Rutile

Rutile is an <a href="/facts/Oxide_mineral/B4ajLX61">oxide mineral</a> composed of <a href="/facts/Titanium_dioxide/T0KWmKcz">titanium dioxide</a> (TiO2), the most common natural form of TiO2. Rarer <a href="/facts/Polymorphism_(materials_science)/bu2tqsB9">polymorphs</a> of TiO2 are known, including <a href="/facts/Anatase/wD932gCW">anatase</a>, <a href="/facts/Akaogiite/yHkSeVh7">akaogiite</a>, and <a href="/facts/Brookite/RAHb2XFS">brookite</a>.
Rutile has one of the highest <a href="/facts/Refractive_index/yjkzvgeE">refractive indices</a> at <a href="/facts/Visible_wavelength/frPBh8o5">visible wavelengths</a> of any known crystal and also exhibits a particularly large <a href="/facts/Birefringence/J4lLuR3a">birefringence</a> and high <a href="/facts/Dispersion_(optics)/cUdHnYXz">dispersion</a>. Owing to these properties, it is useful for the manufacture of certain optical elements, especially <a href="/facts/Polarization_(waves)/fP33m0eD">polarization</a> optics, for longer <a href="/facts/Light/jeofpMn4">visible</a> and <a href="/facts/Infrared/44XdJNcc">infrared wavelengths</a> up to about 4.5 micrometres. Natural rutile may contain up to 10% <a href="/facts/Iron/QK1JYy8E">iron</a> and significant amounts of <a href="/facts/Niobium/3zNI8AKp">niobium</a> and <a href="/facts/Tantalum/VwaxMm33">tantalum</a>.
Rutile derives its name from the Latin rutilus ('red'), in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile was first described in 1803 by <a href="/facts/Abraham_Gottlob_Werner/WH8b5tqu">Abraham Gottlob Werner</a> using specimens obtained in Horcajuelo de la Sierra, Madrid (Spain), which is consequently the <a href="/facts/Type_locality_(geology)/ky6QjASt">type locality</a>.

Rutile open-in-new

Rutile