[roo-teel, -tahyl] 
| a common mineral, titanium dioxide, TiO2, usually reddish-brown in color with a brilliant metallic or adamantine luster, occurring in crystals: used to coat welding rods. |
| ru·tile (rōō'tēl', -tīl') n. A lustrous red, reddish-brown, or black mineral, TiO2, used as a gemstone, as an ore, and in paints and fillers. [French, from German Rutil, from Latin rutilus, red; see rutilant.] |
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