What is Hematite?
Hematite is an iron oxide with a red-brown streak, metallic forms and an important role in iron ore deposits.
Mineralogy and structure
The reference formula is Fe2O3. Hematite is classified with the oxides and its crystal system is trigonal. Natural specimens can vary in composition, habit and degree of crystallinity, so the locality and observed form remain important.
Colour and appearance
Typical colours include steel-grey, black, red-brown and earthy red. Lustre, transparency, inclusions and surface condition should be described for the individual specimen rather than inferred from the name alone.
Formation and localities
Hematite forms in or is associated with sedimentary iron formations, hydrothermal veins, soils and metamorphic rocks. Notable collecting regions include Brazil, England, Switzerland, Morocco, Russia and the United States. A precise locality is more useful than a broad country label when it is documented.
Collecting notes
Hematite is useful in a reference collection because its appearance connects mineral chemistry with geological setting. Store specimens dry, protected from impact and clearly labelled with the confirmed material, locality and any treatment history.
