Discover and read the best of Twitter Threads about #EgyptianBlue
Most recents (5)
In today’s #thread, we are going to talk about the first scientific analyses of the pigments employed on the mural paintings of @pompeii_sites, published by Jean-Antoine Chaptal (1809). 
Chaptal was lucky enough to receive 7 pigment samples found at @pompeii_sites from Joséphine de Beauharnais, Napoleon’s wife, Empress of France, and Queen of Italy in 1809.
According to him, the pigments were found in a shop corresponding to a pigment trader. The first sample was a greenish clay, which he found similar to the Verona earth used at that time, a mineral composed of iron silicates (celadonite, glauconite).
In today’s #thread we are going to talk about the manufacturing process and use of black pigments in Roman mural paintings, with examples from @pompeii_sites and @MNR_museo. Let’s go!
Pliny and Vitruvius considered black (called atramentum) an artificial colour, because it required the transformation of raw materials. However, according to Pliny, it could also be found in salt-pits or sulfurous earths, and some painters used to dig up charred human bones.
Nonetheless, the most widespread manufacturing process was the calcination of pine resin in constructions that did not allow an escape for the smoke. The most esteemed black, according to Pliny, was prepared from the wood of Pinus mugo or Pinus cembra.
Today we are going to talk about the variety of pigments and mixtures employed to obtain green hues from Ptolemaic and Roman Egypt to the mural paintings of @pompeii_sites, with a glimpse of the Macedonian tombs at Vergina and the Tomb of the Diver at @paestumparco.
Several mixtures and green pigments have been detected in Ancient Egypt artefacts. Among the pigments, we can list malachite (Cu2CO3(OH)2), chrysocolla ((Cu, Al)2H2SiO5(OH)4·nH2O), Egyptian Green (CaCuSi4O10) and green earth (hydrated iron potassium silicates).
On the other hand, green mixtures were made up of #EgyptianBlue, indigo, orpiment (As2S3) and yellow ochre (FeOOH).
In today’s #thread we will be talking about Late Classical and Hellenistic painting techniques, from Greece and Macedon to present-day Bulgaria and Italy. Aren’t these Tyrian purple backgrounds from Tomb III (Aghios Athanassios) and the Amazon sarcophagus just stunning?
There are two main painting techniques associated to Late Classical and Hellenistic art: secco, which makes use of a binding medium to fix the pigments, and fresco, which is based on the application of the pigments on a fresh lime plaster.
Two binding media have been documented in examples dating back to this period: gum arabic and egg tempera. The superb marble throne found at the Tumb of Eurydice (Vergina) was painted using gum arabic as binding medium for the secco technique.
Let’s talk about #EgyptianBlue, its manufacture and use from Egypt to the Iberian Peninsula, with a special insight into the Vesuvian area, where this pot containing original pigment has been excavated.
This bowl is conserved, among others containing several different pigments, at the Applied Research Laboratory of @pompeii_sites, and has been in-situ analysed via non-destructive portable techniques.
“Blue was first manufactured at Alexandria…” This is what Vitruvius wrote on the origin of the first man-made pigment, present in this tiny scarab beetle.
