MORE ABOUT RUTILE
Rutile is a mineral composed of titanium dioxide, TiO2, being one of the three polymorphs of TiO2:
Rutile, a usually tetragonal mineral of prismatic habit, usually with mottled crystals;
Rutile has a subconcoidal fracture, is brittle, with hardness 6 to 6.5, relative density 4.1 to 4.2, metallic to adamantine shine, usually brown or red, sometimes yellow, blue or violet. It is transparent to opaque. The natural rutile is usually opaque or very dark red. Rutile can contain up to 10% iron. Rutile is the most stable form of titanium dioxide and is produced at higher temperatures, with brookite forming at lower temperatures and the octahedrite at even lower temperatures.