The hunk weighs a whopping five pounds and measures more than six inches long. Simona Murrone / Colosseum Archaeological ParkIn the ruins of Romes opulentDomus Aurea palace, archaeologists have uncovered an array of ancient pigments used by artisans to paint the walls of the emperor Neros stately marble home with resplendentfrescoes some 2,000 years ago.Inside the remnants of workshops, the archaeologists recovered an amphora containing yellowocher and small jars filled with reddish pigments likerealgar and red ocher. They also came across basins where artisans would have mixed pigments with water.But the highlight of the haul is a solid hunk ofEgyptian blue, a rare pigment prized for thousands of years for its shimmering and ethereal qualities. Yellow ocher discovered inside a Roman amphora Simona Murrone / Colosseum Archaeological ParkThe fascination conveyed by the depth of blue of this pigment is incredible, says Alfonsina Russo, the director of the Colosseum Archaeological Park, which manages the Domus Aurea, in astatement, per a translation byGizmodosMargherita Bassi. The Domus Aurea once again moves [us] and restores the brilliance of the colors used by the painters who skillfully decorated the rooms of this precious and refined imperial palace.Unlike ocher and realgar, which occur naturally, Egyptian blue is a synthetic pigmentproduced by firing a mixture of silica, limestone and minerals containing copper and sodium carbonate at high temperatures. It is considered the worldsoldest known synthetic pigment.As its name suggests, the blue pigment originated inancient Egypt. Dating to at least the third millennium B.C.E., it became an essential element in decoration and design, according toLa Brjula Verdes Guillermo Carvajal. It provided thesubtle shading on ancient Egyptian portraits and the vivid coloring of faience funeraryfigurines.The Roman architectVitruvius recorded the recipe in his treatise De Architectura in the first century B.C.E., reflecting how the color spread through the Mediterranean world and found a thriving home in the Roman Empire, where researchers have since identified Egyptian blue in theBaths of Titus and the walls of Pompeii. Egyptian blue is the world's oldest known synthetic pigment. Simona Murrone / Colosseum Archaeological ParkOften, archaeologists discover traces of Egyptian blue that are all butimperceptible to the human eye. For instance, with the help of microscopes and luminescent imaging, researchers at the British Museum discovered that Egyptian blue once adorned theParthenon marbles. In other cases, the pigment has been found in fine powders or small spheres, according to the statement.But what makes this discovery at the Domus Aurea all the more remarkable is the whopping size of the Egyptian blue ingot in question, which weighs more than five pounds and measures six inches long. Basins where the pigments were hydrated and mixed with water Simona Murrone / Colosseum Archaeological ParkThe great size of this sample suggests widespread usage in the palaces frescoes, as well as the specialized skills of the masters working on the imperial project, asArtnets Min Chen writes.Archaeologists are investigating whether this sample of Egyptian blue was produced domesticallyin a place likeCuma,Liternum orPozzuoli, which Vitruvius noted as a production hubor exported from an Egyptian city like Alexandria, according to the statement.Researchers once thought that the pigment's recipe was lost after the fall of the Roman Empire, only to be rediscovered in the 19th century by the British chemistHumphry Davy. But in recent years, Egyptian blue has beenfound in Renaissance artworks, including Giovanni Battista Benvenutos 1524 paintingSt. Margaret andRaphaels 1512 fresco The Triumph of Galatea. Raphael's 1512 fresco The Triumph ofGalateauses the Egyptian blue pigment. Public domain via Wikimedia CommonsArtists like Raphael andDomenico Ghirlandaio were known to sneak into the ruins of Neros home to admire and take artisticinspiration from the frescoes completed in the first century C.E., according to Artnet.The presence of Egyptian blue in the Domus Aurea suggests a colorful past that inspired another generation of Italian painters to recreate the vivid blue in their own work. As the statement notes, the discovery provides another link between the art of antiquity and the art of the Renaissance.Get the latest stories in your inbox every weekday.Filed Under: Ancient Civilizations, Ancient Egypt, Ancient Greece, Ancient Rome, Archaeology, Art, Arts, Cool Finds, Egypt, Painters, Painting, Renaissance, Roman Empire, Visual Arts