Hematite is a stunning mineral that naturally occurs in a variety of colors, including black, steel-gray, silver-gray, brown, reddish-brown, and vibrant red. Known as a major ore of iron, it’s prized not only for its beauty but also for its electrical conductivity. Hematite comes in several fascinating varieties, including kidney ore, martite (pseudomorphs after magnetite), iron rose, and specularite (specular hematite). Regardless of its form, all hematite exhibits a distinctive rust-red streak, making it easy to identify.
 
While hematite is harder than pure iron, it is also more brittle, which gives it a unique texture and appearance. "Kidney ore" refers to the botryoidal, mammillary, or reniform shapes that this mineral often forms. A related mineral, maghemite, is a polymorph of hematite, sharing the same chemical formula but with a spinel structure similar to magnetite.
 
Hematite is commonly found in large deposits within banded iron formations. The gray variety, in particular, often forms in places with still, standing water, such as mineral hot springs or lakes like those found in Yellowstone National Park. Here, hematite precipitates out of the water, collecting in layers at the lake’s bottom. It can also form in volcanic environments without the presence of water.
 
Additionally, hematite can form as secondary clay-sized crystals due to weathering processes in soil. Alongside other iron oxides like goethite, it contributes to the vibrant red color seen in many highly weathered soils, especially in tropical or ancient regions. Hematite is a beautiful and versatile mineral, ideal for collectors, jewelry, or anyone drawn to its rich colors and history.
 
Location, Morocco