Indian yellow

Indian yellow is a complex pigment consisting primarily of euxanthic acidsalts (magnesium euxanthate and calcium euxanthate), euxanthone, and sulfonated euxanthone. It is also known as purree, snowshoe yellow, gaugoli, gogili, Hardwari peori, Monghyr puri, peoli, peori, peri rung, pioury, piuri, purrea arabica, pwree, jaune indien (French, Dutch), Indischgelb (German), yìndù huáng (Chinese), giallo indiano (Italian), and amarillo indio (Spanish).

The crystalline form dissolved in water or mixed with oil to produce a transparent yellow paint which was used in Indian frescoes, oil painting, and watercolors. After application Indian yellow produced a clear, deep, luminescent orange-yellow color which, due to its fluorescence, appears especially vibrant and bright in sunlight. It was said to have a disagreeable odour. It was most used in India in the Mughal period and in Europe in the nineteenth century, before becoming commercially unavailable circa 1921.

The origin and manufacture of Indian yellow had long been disputed partly due to variations among the sources themselves which included both pure materials and mixtures of chrome salts, dyes of plant origin, and dyes of animal origin. Studies in 2018 of a sample collected by T. N. Mukharji in 1883 give credibility to his observations that it was obtained from concentrated urine from cows fed on a diet of mango leaves.