Blue Ridge Violet Hematite Pigment

Violet Hematite is a natural red iron oxide from the heart of the Blue Ridge Mountains of Virginia. It has a high iron content (over 98%), giving it a deep brown red with a plate-like micaceous particle structure.

Natural red iron oxides are opaque, permanent, and have excellent covering power. They are strong absorbers of ultraviolet light. The best bluish shades are Indian red; the yellowish shades light red, English red, and Venetian red. Formerly, there was much confusion in the terminology of the red oxides; the terms given in this list are those specified in the ASTM Standard.

Origin and History

Natural red iron oxide is based on the mineral ore hematite. The word hematite comes from the Greek word hema, meaning blood, and was named "bloodstone" in ancient Greece (Theofrastus, c. 325 B.C.), implying that the mineral is blood red in color. Hematite is an important iron ore; its blood-red color in the powdered form lends itself well as a pigment. Hematite is among the oldest pigments known to humankind and has been used by every major civilization.

Source

In nature, hematite rarely occurs as crystals but usually as nodules or earthen masses. The color of the crystalline form varies from steel-gray to black, while crypto-crystalline hematite is dull red to bright red. This common mineral is found in deposits of the most diverse types. 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 is 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 are found worldwide and have been used as pigments since prehistory.

Permanence and Compatibility

Pigments made from the mineral hematite are dependable in mixtures with all other permanent pigments and are considered permanent with considerable tinting strength and opacity. They do not react with solvents and are indifferent to alkalis but are partially soluble in acids. Zinc white and hematite yield excellent flesh tints.

Oil Absorption and Grinding

Natural red iron oxide absorbs a moderate amount of oil. The oil absorption ratio is 158 parts by weight of raw linseed oil to 100 parts by weight of pigment. If the measurement were grams, red iron oxide would require 18 grams (by weight) of linseed oil to grind 100 grams (by weight) of pigment to form a stiff paste. It forms an average drying oil paint and a hard, somewhat flexible film.

Toxicity

Natural red iron oxide is not considered toxic, but care should be taken in handling the dry powder pigment to avoid inhaling the dust.