Hematite is marked by a contrast in appearance, it's dark, tar-like color nonetheless glistening with a shining luster. This compound has been used by humans for millennia, its homogenous and dense structure well-suited for toolmaking. Hematite can also be found lining cave walls in paleolithic paintings, the pigment used across the world in some of the oldest known works of art.

This specimen is a Polished Botryoidal Hematite cluster, demonstrating the compound's bulbous botryoidal shape, formed over millions of years. Each hematite cluster is shipped in a sturdy carton with an informational card which serves as certificate of authenticity. You can see all the currently available hematite specimens as well as our hematite portraits in the collection below.

Hematite, or iron(III) oxide (Fe₂O₃), is a reddish-black mineral forming through the oxidation of iron-rich rocks and minerals, often in the presence of water. One of the most remarkable terrestrial examples of this process can be seen at Rio Tinto in Spain (above), where acidic waters rich in dissolved iron flow, resulting in striking, rust-colored streams.

Similarly, Mars has offered its own peculiar iron oxide formations, famously dubbed "Martian blueberries." These small, spherical concretions were discovered by the Mars Exploration Rover, Opportunity, not Curiosity, and they consist predominantly of hematite, hinting at past aqueous conditions on Mars. This striking similarity between Earth and Mars provides valuable insights into the planetary processes involving water and iron minerals.

Hematite is an iron oxide with a lustrous sheen and color that ranges from deep black to a lighter browns, appearing darker in more dense material. The mineral is fine-grained and largely homogenous. Red flecks can appear in samples that are less dense, as in weathered cracks or as individual mineral particles in soils. Because of its homogenous structure, hematite was often used to make tools like Mesopotamian cylinder seals used in bookkeeping circa 2600-1200 BCE.

Hematite is also the source of ochre pigment, a relatively common substance on the Earth’s surface and a ubiquitous piece of early human life. In its base form, ochre is a rich, iron-oxide hematite mixed with sand or clay. The exact composition of ochre differs from region to region, but it spans a spectrum of color between reds, browns, and yellows. Early humans would mix this pigment with oils to create a simple but effective paint. 

The evidence of this paint is found across the world in sites like the Cueva de las Manos in Argentina where for thousands of years, innumerable artists left their mark on the cave’s walls. Beyond its appearance in cave art, humans used ochre for sun protection, insect repellant, treating animal hides, body paint, food preservation, and even as a medicinal salve. Recent research has found that human production of ochre stretches back 250,000 years.