Hematite is a common iron oxide mineral and an important source of iron.
An ore is a rock that contains minerals with important elements, including metals.
Although hematite is a mineral, not a rock, it forms part of an iron ore rock. The iron ore rock is mined, and the hematite within is processed to extract iron.
Hematite, which is composed of 70% iron and 30% oxygen, is available in abundance around the world.
Its colour ranges from black to silver grey, brown to reddish brown and can also be red.
The red hue on Mars comes from fine grains of hematite that blow around during dust storms.
Hematite generally has weak or no magnetic properties.
Hematite often occurs with other iron minerals such as goethite and magnetite.