Orange mineral

Description

A bright orange pigment composed of Lead tetroxide. Orange mineral is synthetically made by calcining lead white or heating red lead oxide to a higher temperature. Although orange mineral has the same chemical composition as red lead oxide, it has a different crystalline structure. Orange mineral is not sufficiently lightfast for use as an artist pigment. It is used in industrial paints, primers and printing inks.

Synonyms and Related Terms

laranja mineral (Port.); orange lead

Physical and Chemical Properties

• Toxic by inhalation or ingestion.
• Skin contact may cause irritation or ulcers.
• Carcinogen, teratogen, suspected mutagen.

Physical and Chemical Properties

Soluble in glacial acetic acid, hot HCl, nitric acid with peroxide present. Insoluble in water and ethanol.

Composition	Pb3O4
Density	9.0 g/ml

Resources and Citations

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p.445

• Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996