Rutile
Mineral TiO2
Also called Sagenite and Nigrine
About it
Striated red-brown to black prisms, often in knee-shaped twins, and golden needles inside quartz. Graves Mountain, Georgia, is a classic source, and Bahia, Brazil, gives stars of rutile on hematite.
- Type
- Mineral
- Group
- Oxide, rutile group
- Formula
- TiO2
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 4.2–4.3
- Streak
- pale brown
- Lustre
- adamantine (diamond-like), submetallic
- Crystal system
- Tetragonal
- Colours
- red-brown, red, golden yellow, black
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- good prismatic; conchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.