New sources for historic pigments

Before the Industrial Revolution, many pigments were known by the location where they were produced. Pigments based on minerals and clays often bore the name of the city or region where they were mined. Raw Sienna and Burnt Sienna came from Siena, Italy, while Raw Umber and Burnt Umber came from Umbria. These pigments were among the easiest to synthesize, and chemists created modern colors based on the originals that were more consistent than colors mined from the original ore bodies. But the place names remained. Historically and culturally, many famous natural pigments have been replaced with synthetic pigments, while retaining historic names. In some cases the original color name has shifted in meaning, as a historic name has been applied to a popular modern color. By convention, a contemporary mixture of pigments that replaces a historical pigment is indicated by calling the resulting color a hue, but manufacturers are not always careful in maintaining this distinction. The following examples illustrate the shifting nature of historic pigment names: Titian used the historic pigment Vermilion to create the reds in the great fresco of Assunta, completed c. 1518. Indian Yellow was once produced by collecting the urine of cattle that had been fed only mango leaves[citation needed]. Dutch and Flemish painters of the 17th and 18th centuries favored it for its luminescent qualities, and often used it to represent sunlight[citation needed]. In the novel Girl with a Pearl Earring, Vermeer's patron remarks that Vermeer used "cow piss" to paint his wife.[13] Since mango leaves are nutritionally inadequate for cattle, the p actice of harvesting Indian Yellow was eventually declared to be inhumane[citation needed]. Modern hues of Indian Yellow are made from synthetic pigments. Ultramarine, originally the semi-precious stone lapis lazuli, has been replaced by an inexpensive modern synthetic pigment, French Ultramarine, manufactured from aluminium silicate with sulfur impurities. At the same time, Royal Blue, another name once given to tints produced from lapis lazuli, has evolved to signify a much lighter and brighter color, and is usually mixed from Phthalo Blue and titanium dioxide, or from inexpensive synthetic blue dyes. Since synthetic ultramarine is chemically identical with lapis lazuli, the "hue" designation is not used. French Blue, yet another historic name for ultramarine, was adopted by the textile and apparel industry as a color name in the 1990s, and was applied to a shade of blue that has nothing in common with the historic pigment ultramarine. Vermilion, a toxic mercury compound favored for its deep red-orange color by old master painters such as Titian, has been replaced in painters' palettes by various modern pigments, including cadmium reds. Although genuine Vermilion paint can still be purchased for fine arts and art conservation applications, few manufacturers make it, because of legal liability issues. Few artists buy it, because it has been superseded by modern pigments that are both less expensive and less toxic, as well as less reactive with other pigments. As a result, genuine Vermilion is almost unavailable. Modern vermilion colors are properly designated as Vermilion Hue to distinguish them from genuine Vermilion.