Egyptian blue, the oldest synthetic pigment in the world, is recreated

Anti-criticism activists have been in a war against food color for decades, and with one of theirs to have power in the new presidential administration, they have even banned some, but artificial dyes have been used in many products during millennia.

The oldest synthetic pigment in the world, called Egyptian blue, was used about 5,000 years ago. But although its use is known, it was a substitute for expensive minerals such as turquoise or lapislázuli when painting wood, stone and a paper material type called cardboard, there is little evidence of how it was done. He was approached by the Greeks and then the Romans after they conquered Egypt, but at some point they succeeded in the acquisitions for the rehydun caliphate, the Kurdish ayyubids, the moms and the Ottomans who were lost.

Image: McCloy et al.Nature Portfolio Journals Heritage Science

He has long fascinated academics due to the biological, magnetic and optical properties of which ancient people knew nothing. The Egyptian blue pigment emits light in the electromagnetic spectrum of near infrared, so fingerprints and inks to the invisible falsification for the human eye could be used. It even has some chemistry similar to high temperature superconductors.

But it varies from deep blue to gray green and the researchers wanted to know how ancient people made that decision. Or if it simply happened because small variations in the process changed it anymore and nobody really cared, since it was utility instead of art. To create recipesResearchers came up with 12 different mixtures of silicon, copper, calcium and sodium carbonate and temperature ranges used for old crops, approximately 1,000 degrees Celsius. They tested the mixtures at various temperatures for one and 11 hours and compared them with two old Egyptian artifacts.

The most blue secret required approximately 50% of the blue color components. But now you can do yours, at least until activists get a sodium carbonate. And if that is too much work, you can see your samples at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.