A study published in the journal Heritage Science shows how expensive one of the most characteristic pigments used in the decoration of Pompeian houses – the famous Egyptian blue (called caeruleum) – was.
The analysis was conducted on the walls of the so-called “Blue Sanctuary” located in Regio IX in Pompeii, specifically in building IX.10. The team of researchers examined the pigment used to decorate the walls of this room. The study used X-ray microscopy, combining various analytical methods. This allowed the researchers to precisely determine the amount of pigment applied to the walls using the fresco technique.
Relying on information provided by Pliny the Elder in his work “Natural History”, the researchers estimated that the most likely pigment used in the room was caeruleum Vestorianum, which cost approximately 11 denarii per Roman libra (approx. 327 g). Analysis of the pigment quantity revealed that approximately 2.8 to 5 kg of blue paint was used for the decoration.
At this price, the cost of the pigment alone was approximately 93-168 denarii. For comparison, in the first century CE, a loaf of bread cost about 0.125 denarii, so the value of the pigment used was equivalent to 744-1,344 loaves of bread. This was also approximately 50-90% of a Roman legionary’s annual pay, which was approximately 187 denarii. This means that the intense blue decorations in Pompeian homes were a clear symbol of the owner’s wealth.
