Hematite is a fairly common mineral consisting of iron and oxygen (Fe2O3). Hematite can occur in a variety of colors, from black to steel or silver-gray, brown to reddish brown, or red. The name hematite is derived from the Greek word for blood, not for its red color itself, but for the trace it leaves behind when scratched or powdered. The spectral signature of hematite was seen on the planet Mars by the infrared spectrometer on the NASA Mars Global Surveyor (“MGS”) and 2001 Mars Odyssey spacecraft in orbit around Mars.
Here's some of the largest, plumpest ones out there.Read more