Hematite

General Information and Properties

• Hematite is a mineral found in rocks and soils.
• Chemical formula: Fe2O3.
• Belongs to the oxide minerals category.
• Trigonal crystal system, hexagonal scalenohedral crystal class.
• Metallic to splendent luster, bright red to dark red streak.
• Opaque, specific gravity of 5.26, density of 5.3.

Hematite Varieties and Etymology

• Varieties include kidney ore, martite, iron rose, and specularite.
• Rust-red streak.
• Harder than pure iron but more brittle.
• Maghemite is a polymorph of hematite.
• Large deposits found in banded iron formations.
• Name derived from the Greek word for blood.
• Used as a pigment since ancient times.
• Hematite residues found in graves dating back 80,000 years.

Magnetism

• Feeble response to a magnetic field, not attracted to an ordinary magnet.
• Antiferromagnetic below the Morin transition at 250K.
• Canted antiferromagnet or weakly ferromagnetic above the Morin transition and below Néel temperature at 948K.
• Magnetic structure is essentially antiferromagnetic with spin canting.
• Magnetic properties differ between bulk hematite and nanoscale counterparts.

Mine Tailings

• Hematite present in waste tailings of iron mines.
• Magnetation process used to extract waste hematite from old mine tailings.
• Falu red, a pigment, originally made from tailings of the Falu mine.
• Hematite in mine tailings can be recycled through various processes.
• Proper management of mine tailings is important to prevent environmental contamination.

Applications

• Hematite used in jewelry components, mourning jewelry, gilding, and engraved gems.
• Hematine, a synthetic material sold as magnetic hematite.
• Used as a pigment in human pictorial depictions throughout history.
• Component of red, purple, and brown iron-oxide pigments.
• Important in ochre, sienna, and umber pigments.
• Used in industrial applications such as iron ore, medical equipment, shipping, coal production, radiation shielding, and ship ballasts.
• Hematite can be used to separate coal powder from impurities.
• Various examples and images in the gallery section.

Hematite Data Sources