, also spelled as haematite
, is a common iron oxide
with a formula called Fe2O3
and has been widespread in rocks and soils.
Hematite forms in the shape of crystals through the rhombohedral lattice system
, and it has the same crystal
structure as ilmenite
. Hematite and ilmenite form a complete solid solution
at temperatures above 950 Â°C (1,740 Â°F).