Hematite

Hematite is the iron oxide mineral Fe₂O₃ and a major source of iron. It commonly appears black or gray as a crystal and leaves a red-brown streak.

Iron(III) oxide: An inorganic compound of iron and oxygen with formula Fe₂O₃. Hematite is the mineral form of this compound.
Iron ore: Rock or mineral material mined for economically recoverable iron. Hematite is one of the world’s principal iron ores.
Banded iron formation: Ancient sedimentary rock composed of alternating iron-rich and silica-rich layers. These formations contain vast deposits of hematite-bearing iron ore.
Elba Island: An Italian island in the Tyrrhenian Sea with long-standing iron mining. Its hematite deposits supplied a historically important source of iron.
Corundum structure: A crystal structure shared by corundum and several sesquioxide minerals. Hematite’s iron and oxygen atoms are arranged in this structure.
Ironmaking: The industrial production of metallic iron from iron-bearing materials. Smelting reduces hematite to iron in blast furnaces.
Great Oxidation Event: A major rise in atmospheric oxygen roughly 2.4 billion years ago. Oxygen released by early life helped precipitate iron oxides in ancient oceans.
Lake Superior iron ranges: A group of iron-mining districts around Lake Superior in North America. Their Precambrian rocks contain major hematite-rich ore deposits.
Mohs scale: A scale that ranks minerals by their resistance to scratching. Hematite’s hardness helps distinguish it from other iron oxides.
Blast furnace: A tall furnace that extracts iron from ore using hot air and carbon-rich fuel. It is a major route for processing hematite ore.

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