The mineral hematite is the basis for natural red iron oxide. Hematite is derived from the Greek word hema, which means blood, and was known as "bloodstone" in ancient Greece (Theofrastus, c. 325 B.C. ), implying that the mineral is blood red in color. Hematite is an important iron ore, and its blood red powdered color lends itself well to use as a pigment. Hematite is one of the world's oldest pigments, having been used by every major civilization and epoch.
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Hematite occurs in nature as nodules or earthen masses rather than crystals. The crystalline form ranges in color from steel-gray to black, whereas crypto-crystalline hematite is dull red to bright red. This common mineral can be found in a wide range of deposits.
There are several varieties of hematite, two of which are suitable for use as pigments: oolitic hematite, which is a friable earth composed of small rounded grains of dark red color that are lustrous and greasy to the touch; and hematite rose, a fine-crystalline and crypto-crystalline form of hematite of red color, which are usually encountered in friable earthen masses or reniform aggregates of bladed crystals in a circular arrangement giving the appearance of a rose. Red iron oxides (hematite) deposits can be found all over the world and have long been used as pigments.
