Editing Rutile (section)

==Application==
[[File:Rutile needles.jpg|thumb|Acicular crystals of rutile protruding from a [[quartz]] crystal]]
In large enough quantities in beach sands, rutile forms an important constituent of [[heavy mineral]]s and [[ore deposit]]s. Miners extract and separate the valuable minerals&nbsp;–&nbsp;e.g., rutile, [[zircon]], and [[ilmenite]]. The main uses for rutile are the manufacture of [[refractory|refractory ceramic]], as a [[pigment]], and for the production of [[Titanium metallurgy|titanium metal]].

Finely powdered rutile is a brilliant white pigment and is used in [[paint]]s, [[plastic]]s, [[paper]], foods, and other applications that call for a bright white color. [[Titanium dioxide]] pigment is the single greatest use of titanium worldwide. [[Nanoparticle|Nanoscale particles]] of rutile are transparent to [[Visible spectrum|visible light]] but are highly effective in the [[Absorption (electromagnetic radiation)|absorption]] of [[ultraviolet]] radiation ([[sunscreen]]). The UV absorption of nano-sized rutile particles is blue-shifted compared to bulk rutile so that higher-energy UV light is absorbed by the nanoparticles. Hence, they are used in [[sunscreen]]s to protect against UV-induced skin damage.

Small rutile needles present in [[gemstone|gems]] are responsible for an [[optical phenomenon]] known as [[asterism (gemmology)|asterism]]. Asteriated gems are known as "star" gems. Star [[sapphire]]s, star [[ruby|rubies]], and other star gems are highly sought after and are generally more valuable than their normal counterparts.

Rutile is widely used as a [[Shielded metal arc welding|welding electrode covering]]. It is also used as a part of the [[ZTR index]], which classifies highly weathered sediments.

=== Semiconductor ===
Rutile, as a large band-gap [[semiconductor]], has in recent decades been the subject of significant research towards applications as a functional oxide for applications in [[photocatalysis]] and [[Magnetic semiconductor|dilute magnetism]].<ref>[https://arxiv.org/abs/1304.1854 Magnetism in titanium dioxide polymorphs] J. Applied Physics</ref> Research efforts typically utilize small quantities of synthetic rutile rather than mineral-deposit derived materials.