5,000-Year-Old Color Reborn: Scientists Recreate Ancient Egyptian Blue

Researchers recreated ancient Egyptian blue pigment and uncovered insights into its production, variability, and future tech potential.

A team of researchers led by Washington State University has successfully recreated Egyptian blue, the world’s oldest synthetic pigment, originally used in ancient Egypt around 5,000 years ago.

In a study published in NPJ Heritage Science, the team experimented with different raw materials and heating durations to create 12 pigment recipes. These findings offer valuable insights for archaeologists and conservation scientists studying ancient Egyptian artifacts. The project was a collaboration with the Carnegie Museum of Natural History and the Smithsonian’s Museum Conservation Institute.

“We hope this will be a good case study in what science can bring to the study of our human past,” said John McCloy, first author on the paper and director of WSU’s School of Mechanical and Materials Engineering. “The work is meant to highlight how modern science reveals hidden stories in ancient Egyptian objects.”

Historical context and lost techniques

Although Egyptian blue was highly valued in ancient times, there is little archaeological evidence explaining how it was made. It served as a substitute for costly minerals such as turquoise and lapis lazuli and was used to paint wood, stone, and a papier-mâché-like material called cartonnage.

Depending on the specific ingredients and processing time, the pigment’s color could range from deep blue to dull gray or green. After its use by the Egyptians, the pigment was adopted by the Romans, but by the Renaissance, the method of producing it had largely been forgotten.

According to McCloy, interest in Egyptian blue has grown in recent years because of its unique optical, magnetic, and biological properties that offer promising technological applications. The pigment emits light in the near-infrared range of the electromagnetic spectrum, which is invisible to the human eye.

This property makes it useful for applications such as fingerprint detection and counterfeit-proof inks. It also shares chemical similarities with high-temperature superconductors.

“It started out just as something that was fun to do because they asked us to produce some materials to put on display at the museum, but there’s a lot of interest in the material,” said McCloy, who, in addition to being a professor in materials science and engineering, has a master’s degree in anthropology.

Experimenting with ancient materials

To understand its makeup, the researchers, including a mineralogist and an Egyptologist, created 12 different recipes of the pigment from mixtures of silicon dioxide, copper, calcium, and sodium carbonate. They heated the material at about 1000 degrees Celsius for between one and 11 hours to replicate temperatures that would have been available for ancient artists.

After cooling the samples at various rates, they studied the pigments using modern microscopy and analysis techniques that had never been used for this type of research, comparing them to two ancient Egyptian artifacts.

Egyptian blue included a variety of blue colors, depending on where they were made and their quality. The researchers found that the pigment is highly heterogeneous.

“You had some people who were making the pigment and then transporting it, and then the final use was somewhere else,” said McCloy. “One of the things that we saw was that with just small differences in the process, you got very different results.”

Surprising simplicity of the bluest shade

The researchers found that, in fact, to get the bluest color requires only about 50% of the blue-colored components.

“It doesn’t matter what the rest of it is, which was really quite surprising to us,” said McCloy. “You can see that every single pigment particle has a bunch of stuff in it — it’s not uniform by any means.”

The samples created are currently on display at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania and will become part of the museum’s new long-term gallery focused on ancient Egypt.

Reference: “Assessment of process variability and color in synthesized and ancient Egyptian blue pigments” by John S. McCloy, Edward P. Vicenzi, Thomas Lam, Julia Esakoff, Travis A. Olds, Lisa S. Haney, Mostafa Sherif, John Bussey, M. C. Dixon Wilkins and Sam Karcher, 22 May 2025, npj Heritage Science.
DOI: 10.1038/s40494-025-01699-7

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