A dense and relatively hard iron oxide, hematite is the most abundant iron ore, with high iron content (70%). Much hematite is a soft, fine-grained earthy form used as pigment called red ocher. Purified hematite (rouge) is used to polish plate glass and jewelry. From the Greek haimatitis, meaning “blood red,” hematite streaks red. Hematite has been used for blood disorders and wounds, as well as for protection and grounding. The Lake Superior district is the world’s largest producer; other major deposits are found in Brazil, Australia, and China.