Hematite is a metallic gray iron oxide mineral, and the same stone of a differing variety as specularite.
Ancient Egyptians used it to stanch blood and promote the formation of blood cells. In the Middle Ages is was known as the “blood stone” due to the fact that the water used to polish it would turn red during the process, as if the stone were bleeding. Native American folklore states that war paint made from hematite will make one invincible in battle. People in the eighteenth and nineteenth centuries wore hematite jewelry during mourning.
Scientists of the Mars Exploration Rover Project believe that deposits of hematite on Mars may help prove whether large amounts of liquid water ever flowed on Mars’ surface. They say that where water was, life may have had a chance to thrive as well.