Banded iron formation
Rock
Also called BIF, Tiger iron, Taconite, and Jaspilite
About it
Ancient rock of thin alternating bands of iron oxide (hematite or magnetite) and red jasper or grey chert, mostly over 1.8 billion years old; magnetite-rich kinds attract a magnet. The main iron ore of the Mesabi Range, Pilbara, and Labrador Trough.
- Type
- Rock (sedimentary)
- Group
- Sedimentary (chemical)
- Streak
- red-brown or black
- Lustre
- metallic, submetallic, dull
- Colours
- red, black, silver-grey, brown, gold, banded
- Transparency
- opaque
- Magnetic
- Weakly
Typical values: real specimens vary. For more, see mindat.org.