Large piece of Egyptian blue found at the Golden Palace – History

Excavations at Nero’s Domus Aurea, built on Rome’s Oppian Hill after the fire of AD 64, revealed a rare Egyptian blue ingot. Archaeological finds of this pigment usually come in small chunks or powder form, but the Domus Aurea chunk stands 6 inches tall and weighs 5.3 pounds, an unusual size for an Egyptian blue.

Egyptian blue is not a naturally occurring pigment. It is produced through a complex process that boils a mixture of silica, limestone, copper-containing minerals and sodium carbonate at extremely high temperatures. Because it is so expensive to produce, it is used only in the most luxurious painterly artworks, used alone or in combination with other pigments to create subtle effects such as a glow in the eyes and a cool complexion.

As the name suggests, the pigment originated in Alexandria, Egypt, but by the time Nero commissioned frescoes on thousands of square feet of walls, Egyptian blue was already being produced in many places in Italy. Archaeological evidence of blue production has been found at Cumae and Litherno, and Vitruvius mentioned the name of a manufacturer at Pozzuoli.

This is Vitruvius’s passage about the blue color of Egypt On architectureBook 7, Chapter 11:

Blue was first made in Alexandria and later in Puzoli by Vestorius. Its preparation method and the nature of its ingredients deserve our attention. Grind the sand with the natron flowers until the mixture is as fine as flour, then add coarse Cyprian copper shavings, moisten with water and make a paste; roll it into balls with your hands and dry. The ball is then placed in a pottery vessel and placed in the furnace. Thus, copper and sand are heated together by the intensity of fire, giving each other different qualities, thus obtaining the blue color.

The ingot was found in a work space on the west side of the palace, where it was probably ground up and used as pigment. Two large square jars were unearthed, used for slaked lime and processed pigments for the exquisite frescoes that decorated the walls of the Golden House. Analysis of the pigments at the site found yellow ocher in an amphora, and several red pigments in the jar, including realgar and laterite.

The context in which this rare gold ingot was discovered opens up new perspectives not only on Roman artistic production, but also on the influence of Egyptian blue in subsequent centuries. In fact, during the Renaissance, artists such as Raphael rediscovered ancient painting techniques. The famous fresco “The Triumph of Galatea” created in the Villa Farnesina proves that the brilliant Egyptian blue remained a source of inspiration for Renaissance artists, who appreciated its extraordinary color and luminous qualities.

The Domus Domus thus proved to be not only a monument of extraordinary beauty, but also a valuable repository of technical and artistic knowledge that continues to amaze scholars. Current excavations and analyzes are expected to lead to further discoveries that will help to reconstruct a more complete picture of ancient decorative practices and their impact on later generations.