Hematite - Fe₂O₃

Habit: Steel gray to black crystals, may have an iridescent tarnish. Thick to thin tabular, as rosettes, rarely prismatic or scalenohedral. Sometimes micaceous to platy. Also compact columnar, or fibrous (pencil ore), frequently radiating. In reniform masses with smooth Fracture (kidney ore) and in botryoidal and stalactitic shapes. Commonly earthy, or frequently mixed with clay or other impurities. Also granular, friable to compact, concretionary, oolitic. Opaque, transparent on thin edges, Metallic Luster; non-Metallic.

Environment: The most important hematite deposits are sedimentary in origin, either in sedimentary beds or metamorphosed sediments.

Etymology: From the Greek haimatitis for "blood-red", in allusion to the red color, especially in powder form

Hematite is an important ore of iron and in the powdered form can be 'blood red' and can be used as a pigment.