tetragonal Oxides
Rutile
TiO2
Quick Facts
Hardness
6.0
Specific Gravity
4.23
Refractive Index
2.616
Optical Character
Uniaxial +
Crystal Structure
#! Species: Rutile
#! System: Tetragonal (4/mmm)
#! Habit: Elongated prismatic with parallel striations
tetragonal[4/mmm]:{100}@1.0[striation:parallel] + {101}@0.6 | elongate(c:2.0)
tetragonal
4/mmm
{100} {101}
Physical Properties
Crystal Systemtetragonal
Hardness (Mohs)6.0
Specific Gravity4.23
CleavageGood prismatic {110}
FractureSubconchoidal to uneven
LustreAdamantine to metallic
Optical Properties
Refractive Index2.616
Birefringence0.287
Optical CharacterUniaxial +
Dispersion0.33
Pleochroismmoderate: Yellowish-brown / Reddish-brown (Distinct dichroism; visible in faceted stones and thin crystals)
Colours
Reddish-brownBlackGoldenRed (in transmitted light)
Localities
BrazilSwitzerlandUSA (Georgia, Virginia)NorwayAustralia
Common Inclusions
Twinning (knee twin, contact twin)Oriented overgrowths
Crystal Forms
tetragonal_prismtetragonal_dipyramid
Notes
Extreme birefringence (0.287) and dispersion (0.330) - among highest of any mineral; synthetic rutile once used as diamond simulant (Titania)
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Open in Playground #! Species: Rutile
#! System: Tetragonal (4/mmm)
#! Habit: Elongated prismatic with parallel striations
tetragonal[4/mmm]:{100}@1.0[striation:parallel] + {101}@0.6 | elongate(c:2.0)
Related Minerals
Other minerals in the tetragonal system
