A heavy, deep red iron oxide commonly used by the Indians as decorative body paint and pictographs. Steel-gray crystals and coarse-grained varieties are known as specular iron ore; thin scaly types are called micaceous hematite. Much hematite occurs in a soft, fine-grained, earthy form called red ochre or ruddle. Red ochre is used as a paint pigment; a purified form, rouge, is used to polish plate glass. The most important deposits of hematite are sedimentary in origin and the largest deposit is in the Lake Superior district in North America.