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www.mineralgallery.co.za Minerals P-T |
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Rutile |
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Name
Rutile
Chemistry
TiO2 (Oxide)
Uses
As a Ti source and sometimes as a precious stone
Color
Yellow, red,brown to black
Hardness
6 - 6.5 (brittle)
Specific gravity
4.2 - 4.3
Crystal system
Tetragonal. Crysral form: prisms, needles, twinning
Accompanied by:
Anatase, brookite, apatite, titanite
Fracture
Uneven, conchoidal
Luster
Adamantine,sub-metallic,greasy
Cleavage
Perfect on (110), indistinct on (100)
Streak
Yellowish-brown or brownish-red
Similar to:
Ilmenite, cassiterite, tourmaline and zircon
The word rutile comes from the Latin word rutilus which means reddish. It is a fairly common mineral that can often be seen in quartz as golden hairlike inclusions. A variety of rutile is called sagenite, see our specimen for sale below. It is a common mineral. It is mined as a source of titanium. And sometimes it is even facetted as a precious stone.
Rutile, another accessory mineral, occurs in crystals very similar in shape to zircon and is usually found in slender square prisms terminated by a pyramid. But it lacks the glamor of the zircon for, although it has a high luster, rutile found in nature is rarely used as a gem. The mineral is a dark red to black and the occasional stone that is cut has a high metallic luster like gun metal. Long slender needles of rutile are present in rock crystal known as rutilated quartz, or Venus' hairstone.
With advancing technology many minerals, including rutile, have been synthesized. It is made by the Verneuil process, the same method used for the synthesis of ruby and sapphire. Natural rutile is essentially titanium dioxide, TiO2, but usually contains minor impurity elements. By using chemically pure starting material, single crystals of rutile have been produced that are nearly colorless and have only a faint yellow tinge. Cut into stones, this synthetic material with refractive index and dispersion higher than diamond makes dazzling gems. Their hardness is unfortunately low and they are subject to scratching when worn in jewelry.
The rutile that is recovered from beach sands is used as an ore of titanium metal. The largest use of this element is as a paint pigment in the form of the oxide, but rutile is too impure and the pigment is obtained principally from the mineral ilmenite
