Such as the Mona Lisa smile is the icon of the art of 1500, as tha Taj Mahal is the symbol of India and the Christ Redentor is the image of Rio De Janeiro, if you see a panel painted with a red color similar to a purple, shiny and intense, you can’t help to think to Pompeii and to its amazing domus. So much so, that particular color, took the name of “rosso pompeiano”.
But according to recent studies, this wonderful color that has made famous in the world the walls of the rooms of Pompeii and Ercolano, emblem of a land and a piece of history, it would be in reality a transformation of the original color of frescoes due to the gas emissions given off during the eruption of the 79.
Then, what was the real color of the “rosso pompeiano”? It almost seems to be in front of the riddle “what color was the white horse of Napoleon”, but, in our case, nothing ironic and let’s sai it to science: hear hear, almost half of the houses of Pompeii and Herculaneum was ocher!
Researchers say the gases and the incredible warmth emanating by the eruption have acted on the red pigment of the walls making it precisely red: basically the Pompeian red is nothing but a “roasted” ochre yellow!
This myth debunked was actually already known in antiquity: Pliny, in one of his works, explains that by the yellow ochre you can get the red one by roasting the first one. This perpetually changes the color. Tale tipo di tecniche erano molto note agli antichi romani, quindi non ci ha stupito scoprire che mentre alcune case son , si, diventate rosse a causa al calore dell’eruzione, molte altre lo erano già.
A little science: what is the Pompeian red pigment made of?
The Pompeian red is not just a color, but a color range. How did the people of Pompeii produce different shades of Red? The pigment is the cinnabar, a mineral, actually is the major of mercury. This was worked with great care and were made of dust. Vermilion powder obtained from larger grains, measuring between 10 and 25 micron, proved to be much more transparent and opaque, and likely to produce a color similar to red ochre. Several “thickness” of mineral grains, then, were the different hues of red.
But how was this arcane unveiled?Studies have been carried out investigating the dynamics of this transformation: the different types of ochre, the heating rate, temperature, and so on. Observing the walls of Pompeii and Herculaneum, however, you may encounter this phenomenon to the naked eye: just note how the discoloration on the cracks in the wall opened by the eruption, which appears in a different color than the rest of the wall.
Then, for par-level playing field and a sort of “chromatic justice”, would no longer just rename it Pompeian Yellow? Posterity will judge.
Given the massive use that the Romans made of this pigment to fresco the houses you might think they had no idea of the toxicity of this mineral, instead … during ancient Rome they knew very well the unhealthy properties of cinnabar, so that slaves and prisoners they were sent to work in cinnabar mines in Spain: it was practically a death sentence for the prisoners who were forced to live in contact with this toxic mineral.
Fonte immagini: google images