Aureolin

Aureolin (sometimes called Cobalt Yellow) is a pigment used in oil and watercolor painting. Its color index name is PY40 (40th entry on list of yellow pigments). It was first made in 1848 by N. W. Fischer in Breslau and its chemical composition is potassium cobaltinitrite. Aureolin is rated as permanent in oils but darkens and fades easily in wate...
Found on http://en.wikipedia.org/wiki/Aureolin

Aureolin

Cobalt-potassium nitrite. A strong transparent yellow discovered by NW Fischer, Breslau in 1830; first introduced as a paint pigment by Saint-Evre, Paris, 1852; introduced to England about 1860. Supersedes gamboge for water-colour, is suitable for glazing with oils.
Found on http://www.visual-arts-cork.com/colour-art-glossary.htm
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