What's the most expensive color?
Prior to the 19th Century, Lapis Lazuli blue was a very rare color in the art world. And still today it's not used often—instead modern painters might use an ultramarine—because Lapis Lazuli was (and still is) considered to be the most expensive pigment ever made. It's made from grinding up Lapis Lazuli semi-precious stones. Today you might be able to grab five grams for about $360 in Manhattan. But, during the Renaissance the wealthy art patrons wanted the rich almost neon-like blue in religious paintings. See the "Virgin in Prayer" (1640) above.
The history of color in art is often overlooked in the typical audio tours of art exhibits, but at the National Gallery in London a new show, Making Colour, focuses on the chemistry and color in art.
Some colors were quite dangerous, in fact poisonous. In order to make one flower brilliant orange in the painting "Still Life with Bouquet of Flowers and Plums" below, Rachel Ruysch used realgar, aka ruby sulfur. But realgar is an arsenic sulfide, and when made into a powder it's quite toxic.
While I tend toward the scientific stories of color in art, the mythic ones are just as engaging. I'm a Game of Thrones fan, so I particularly loved learning about a red pigment called Dragon's Blood. According to Dangerous Tastes by Andrew Dalby, the red came from mixing the blood of dragons and elephants, where a dragon would ambush an elephant lashing the elephant's legs with its fierce tail. According to the story, the elephant collapses on top of the dragon, breaking its bones and hence the two bloods mixed. But in real life, the "blood" came from a Southeast Asian tree. See below, the Mural in the Villa of Mysteries in Pompeii, painted with Sanguis Draconis.
One of the more interesting or creepy color stories is the making of the once-popular "mummy brown." And it is what you think it is: Deep brown paint made from the ground up remains of mummified Egyptians and their cats.
The human and feline remains were mixed with white pitch and myrrh. By the 1900s, production of the original mummy brown ceased because they literally ran out of available mummies. The modern pigment known as "mummy brown" is actually made from a mix of kaolin, quartz, goethite and hematite (the latter two ingredients determine the brown color).
The Making Colour exhibit will run until September 7, 2014.