Origin of rutile
Examples from the Web for rutile
Biotite, if present, is brown; epidote is yellow or colourless; rutile, apatite and quartz all occur with some frequency.
Rutile is much lighter, 4·2, and the streak light-brown; tourmaline is only 3·2.Getting Gold|J. C. F. Johnson
The principal titanium minerals are rutile (titanium oxide) and ilmenite (iron titanate).
Its most common ore is rutile (TiO2), which resembles silica in many respects.An Elementary Study of Chemistry|William McPherson
Rutile and ilmenite both have high specific gravity and are little affected by weathering.