Hematite
hematite, also spelled as haematite, is a common iron oxide with a formula called fe 2 o 3 and has been widespread in rocks and soilsematite forms in the shape of crystals through the rhombohedral lattice system, and it has the same crystal structure as ilmenite and corundummatite and ilmenite form a complete solid solution at temperatures above 950 c 1,740 f.