Rutiili

Rutiili is a mineral composed of titanium dioxide (TiO2). It is one of the most common naturally occurring crystalline forms of titanium dioxide, with the others being brookite and anatase. Rutiili crystallizes in the tetragonal system, often forming prismatic or acicular crystals. It is known for its high refractive index and luster, giving it a glassy to adamantine appearance. Its color can vary, typically appearing reddish-brown, yellow, or black, though pure rutiili is colorless.

The mineral is relatively hard, ranking 6 to 6.5 on the Mohs hardness scale. Rutiili is found in a variety of geological environments, including igneous rocks, metamorphic rocks, and in placer deposits formed by weathering and erosion. Significant deposits are mined for their titanium content, which is a valuable metal used in alloys, aerospace, and medical implants due to its strength and corrosion resistance. Titanium dioxide itself is widely used as a white pigment in paints, plastics, paper, and cosmetics, valued for its opacity and brightness. Rutiili is also a source for certain gemstones, particularly when exhibiting rutile inclusions within other minerals.