The world’s oldest synthetic pigment, Egyptian blue, has been recreated by a team of researchers from Washington State University. This breakthrough, published in the journal NPJ Heritage Science, provides valuable insights for archaeologists and conservation scientists studying ancient Egyptian materials.

Led by John McCloy, director of WSU’s School of Mechanical and Materials Engineering, the research team collaborated with the Carnegie Museum of Natural History and the Smithsonian’s Museum Conservation Institute to develop 12 recipes for the pigment. These recipes utilized a variety of raw materials and heating times, replicating temperatures available to ancient artists.

Egyptian blue was highly valued in ancient times due to its unique properties and versatility. It was used as a substitute for expensive minerals like turquoise or lapis lazuli and applied to wood, stone, and cartonnage – a papier-mâché-type material. Depending on its ingredients and processing time, the pigment’s color ranged from deep blue to dull gray or green.

The researchers’ work aimed to highlight how modern science can reveal hidden stories in ancient Egyptian objects. After the Egyptians, the pigment was used by Romans, but by the Renaissance period, the knowledge of how it was made had largely been forgotten.

In recent years, there has been a resurgence of interest in Egyptian blue due to its intriguing properties and potential new technological applications. The pigment emits light in the near-infrared part of the electromagnetic spectrum, which people can’t see, making it suitable for fingerprinting and counterfeit-proof inks. It also shares similar chemistry with high-temperature superconductors.

To understand the makeup of Egyptian blue, the researchers created 12 different recipes using mixtures of silicon dioxide, copper, calcium, and sodium carbonate. They heated the material at around 1000 degrees Celsius for between one and 11 hours to replicate temperatures available to 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.

The researchers found that Egyptian blue is highly heterogeneous, with different people making the pigment and transporting it to final uses elsewhere. Small differences in the process resulted in very different outcomes. In fact, to get the bluest color required only about 50% of the blue-colored components, regardless of the rest of the mixture’s composition.

The samples created are currently on display at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania and will become part of the museum’s new long-term gallery focused on ancient Egypt. This research serves as a prime example of how science can shed light on our human past, revealing hidden stories in ancient objects and materials.

The ancient civilization of Arabia was once home to a rich and diverse culture that valued knowledge, trade, and innovation. New research has shed light on one of the most fascinating aspects of their history: the deliberate use of psychoactive and medicinal plants for therapeutic and sensorial practices nearly 2,700 years ago.

Led by Dr. Barbara Huber and Professor Marta Luciani, a team of researchers analyzed organic residues preserved inside Iron Age fumigation devices excavated at the oasis settlement of Qurayyah in northwestern Saudi Arabia. Using advanced metabolic profiling techniques, they detected characteristic harmala alkaloids from the plant Peganum harmala, also known as Syrian rue or harmal.

“This discovery represents chemical evidence for the earliest known burning of harmal not just in Arabia but globally,” says Dr. Huber, lead author of the study. “Our findings shed light on how ancient communities drew upon traditional plant knowledge and their local pharmacopeia to care for their health, purify spaces, and potentially trigger psychoactive effects.”

The integration of biomolecular analysis with archaeology has allowed researchers to identify not just what kind of plants people were using but also where, how, and why. This breakthrough has significant implications for fields such as ethnobotany, medical anthropology, heritage studies, and pharmacognosy – all concerned with the long-term relationship between humans, medicinal plants, and natural resources.

In traditional medicine and household fumigation practices today in the region, Peganum harmala is known for its antibacterial, psychoactive, and therapeutic properties. The new findings underscore its long-standing cultural and medicinal significance.

“This discovery shows the deep historical roots of traditional healing and fumigation practices in Arabia,” adds Ahmed M. Abualhassan, Heritage Commission co-director of the Qurayyah project. “We’re preserving not only objects but also the intangible cultural heritage of ancient knowledge that still holds relevance in local communities today.”

The Western United States is home to some of the most extensive agriculture and growing communities in the country. One of the key factors that sustain these developments is the meltwater from snow-capped mountains, which spills out every spring. For years, models have been used to predict the amount of streamflow available each year, assuming a small fraction of snowmelt enters shallow soil, with the remainder rapidly exiting in rivers and creeks. However, new research from University of Utah hydrologists suggests that this is not the case.

According to their findings, most spring runoff heading to reservoirs is actually several years old, indicating that most mountain snowfall has a long journey as groundwater before it leaves the mountains. This means that there is an order of magnitude more water stored underground than most Western water managers account for, said research leader Paul Brooks.

The team collected runoff samples at 42 sites and used tritium isotope analysis to determine the age of the water. Their findings were published in the journal Nature Communications Earth & Environment and co-authored by Utah geology professors Sara Warix and Kip Solomon in collaboration with research scientists around the West.

Determining the age of mountain streamflow is crucial for predicting how mountain hydrology will respond to changes in climate and land use, according to the researchers. They noted that there would be a lag between input storage and response, which means that even though models have been good in the past, they may not be reliable in the future.

The research also highlighted the importance of incorporating groundwater storage component into models to make good decisions moving forward. Brooks conducted sampling in 2022 while on sabbatical, visiting 42 sites twice, once in midwinter and again during spring runoff.

The state of Utah’s tracking is particularly robust, providing continuous streamflow data dating back 120 years. It’s an unparalleled dataset that has enabled hydrologists to document historic cycles in climate and streamflow that would otherwise have been missed, Brooks said.

According to Solomon, the vast majority of Earth’s fresh, usable water is underground, but just how much is there remains a puzzle. Dating water offers clues, and for determining the age of water, Solomon turns to tritium, a radioactive isotope of hydrogen with a half-life of 12.3 years.

The average age of the runoff sampled in the study varies among the catchment basins depending on their geology. The more porous the ground, the older its water is, since the subsurface can hold a lot more water. By contrast, glaciated canyons with low permeability and shallow bedrock, such as Utah’s Little Cottonwood Canyon, provide far less subsurface storage and younger waters, according to the study.

For decades, federal and state water managers have relied on a network of snowpack monitoring sites to provide data to guide forecasts of water availability for the upcoming year. It’s now clear that such snowpack data doesn’t provide a complete picture, according to the researchers.

“For much of the West, especially the Interior West where this study is based, our models have been losing skill,” Brooks said.

The growing disconnect between snowfall, snowpack volumes and streamflow is driven by variability in these large, previously unquantified subsurface water stores. As a case in point, Brooks highlighted the 2022 water year, which saw snowpacks in many Western states that were near or just below average. Yet that year experienced record low groundwater storage, resulting in much below average spring streamflow.

This new understanding of mountain streamflow has significant implications for water management and resource planning, particularly as the West continues to experience climate variability and change.