Occurrence and Composition
Rutile is a common accessory mineral in intermediate to mafic igneous rocks, and in many metamorphic rocks. It has composition TiO2.

Keys to identifying rutile are its strong yellowish to reddish brown color, high relief, and extreme birefringence.

Important properties
 ·Color - Usually red, red-brown or yellowish-brown. May be pleochroic.
 ·Interference colors - Interference colors may not show due to the strong color of the mineral. When present, they are pastels of very high order.
 ·Relief - very high.
 ·Interference figure - uniaxial (+).

Similar minerals
 ·There are few common minerals that look like rutile.
 ·Hematite generally has a deeper red color and a more irregular, platey, habit.

Rutile in a Whiteschist from the Dora Maira Massif, near Parigi, Italy

The views above show several large grains of brownish rutile (PP). The rutile is surrounded by mostly quartz (on the left and bottom of the photo) and several flakes of clear mica on the right. Rutile has very high birefringence. Just a hint of high order pastel interference colors can be seen here (XP).

Although not distinctive in these photos, kyanite is present just above the two large rutile grains, and also to the left of the smaller grain near the center of the field of view. The kyanite has slightly higher relief than surrounding minerals, but otherwise is hard to pick out. It is clear (PP) and shows first order gray interference colors (XP).

The field of view is 1.5 mm across.

Quartz with Rutile and Muscovite

Most of this view shows quartz. It is characterized by low relief, undulatory extinction and low order interference colors. The brownish, high-relief grains (PP) are rutile. Rutile has very high birefringence but the color of the grain is so strong that its interference colors don't show (XP). A number of small flakes of muscovite are also present. They cannot be distinguished from the quartz in the PP view, but in XP they are marked by their flakey shape and high second order interference colors.

This sample comes from New Ogilby, California. The field of view is about 1.5 mm.

Biotite-Sillimanite Schist , from the Beartooth Mountains, Montana

The PP view shows biotite in various shades of brown, clear quartz, and light yellow brown twinned rutile.The rutile is rimmed by an opaque mineral, probably magnetite. Minor sillimanite is present as one high-relief mass near the right side, just below center. One grain of clear plagioclase is just above the largest rutile. In the XP view, the large black grain is quartz that happens to be near extinction. Biotite shows typical second order interference colors. The rutile shows no distinct interference colors because the color of the grain masks the interference colors.