In ancient times, long before the likes of Yves Klein, Joni Mitchell, Pablo Picasso, or Miles Davis, the color blue held a special significance for the Ancient Egyptians. They used various shades of blue to decorate the tombs of pharaohs, create wall paintings, sculpt statues, and adorn various artifacts. The prized pigment known as “Egyptian blue” was the earliest-known artificial pigment, created by heating malachite, quartz sand, and other materials at high temperatures. This process, later adopted by the Romans, was largely forgotten by the time of the Renaissance.
Recently, a team of researchers embarked on a project to recreate the elusive Egyptian blue pigment. Their findings, published in the journal NPJ Heritage Science, unveiled a dozen different recipes for the prized dye. The team, comprising researchers from Washington State University, the Carnegie Museum of Natural History (CMNH), and the Smithsonian Institution’s Museum Conservation Institute, experimented with various combinations of raw materials and heating times to develop the Egyptian blue pigment.
Using modern technologies and analytical techniques, the researchers explored different powder formulas made from silicon dioxide, copper, calcium, malachite, and sodium carbonate. These formulas were then fired at high temperatures and studied using microscopy, X-ray diffraction, and Raman spectroscopy. The results were compared to modern commercial pigments and Ancient Egyptian artifacts from the CMNH collection.
The study revealed that Egyptian blue is highly inconsistent, with results varying significantly based on changes in the production process. Longer treatment at high temperatures and slower cooling phases resulted in richer, bluer pigments. Surprisingly, the most vibrant hues only required about 50 percent of blue-colored components, showcasing the complexity of the pigment.
John S. McCloy, a lead author of the study, highlighted the surprising findings, noting that each pigment particle contained a diverse range of components. The project, initially undertaken for a museum exhibit, evolved into a deep dive into ancient pigment-making techniques, shedding light on the mysteries of Egyptian blue.
The recreated Egyptian blue samples are currently on display at the CMNH as part of the “Stories We Keep” exhibition, which explores modern scientific research on Egyptian antiquity and conservation. In the future, these mixtures will be featured in the long-term exhibition “Egypt on the Nile,” providing insights into the ancient art of creating the elusive Egyptian blue pigment.
