A purple dye obtained from marine gastropods of the genus Murex (such as Murex brandaris L. and Purpura lapillus L.) found on the shores of the Mediterranean Sea and the Atlantic coast of Europe and the British Isles. Murex purple, also called Tyrian purple and red whelk, was used in Greek and Roman times for dyeing togas and in the Middle Ages for decorating manuscripts. The mollusks secrete a yellowish liquid that oxidizes to a purplish red in bright sunlight. One mollusk only produces one drop of colorant so large numbers were needed to produce enough dye for an entire cloth. Hence, the dye was very expensive. When a synthetic coal tar dye of the same composition (6,6'-dibromoindigo) was developed in 1904, the natural material became obsolete.
Synonyms and Related Terms
murex purple; 6,6'-dibromoindigo; Natural Blue 3; CI 75190; Murex brandaris; Purpura lapillus; Tethys norfolkensis ; Epitonium australe (Violet snails, leadder shells); púrpura imperial (Esp.); pourpre (Fr.); púrpura (Port.); Grecian purple; purple of the ancients; whelk red; ostrum; purpurissum; Imperial purple; Royal blue; Imperial purple
Insoluble in organic solvents and water. Unaffected by alkalis. The color is lightfast except when exposed to nitric acid or chlorine bleaches.
° A. Wallert, Studies in Conservation, 40, pp. 17-188, 1995. ° J.K. Allan, "Tyrian Purple: An Ancient Industry" Australian Museum Magazine, 1934, 5(5), pp. 147-151.
Sources Checked for Data in Record
- R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
- Helmut Schweppe, Schweppe color collection index and information book
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 283
- Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
- Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
- Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
- Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
- The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996 Comment: "Pigments"
- Colour Index International online at www.colour-index.org