Rutile
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameRutile
Chemical FormulaTiO2
Mohs Hardness6.5
Crystal Systemtetragonal
Lustervitreous
Streak Colorbrownish-red
Cleavagegood on {110} and {100}
Fracturesubconchoidal to uneven
Specific Gravity4.23
Colorsreddish-brown, black, yellow, red, violet, bluish
Transparencyopaque to translucent
Type LocalityCavradi gorge, Curnera Valley, Tujetsch (Tavetsch), Vorderrhein Valley, Grischun (Grisons; Graubünden), Switzerland
Mineral GroupOxides
Usestitanium ore, pigment, gemstone
Associated Mineralshematite
Rarityuncommon
Description
The image displays reddish-brown to black, prismatic, and often striated crystals of rutile, some appearing needle-like, embedded within or associated with a matrix that includes hematite.
Geological Context
Rutile is a common accessory mineral found in various igneous and metamorphic rocks, particularly high-grade metamorphic rocks like gneisses and schists, and sometimes in pegmatites and hydrothermal veins. It is also found as a detrital mineral in placer deposits due to its high specific gravity and resistance to weathering.
