Read on Twitter
In today’s #thread, we will be talking about yellow pigments employed in the mural paintings of @pompeii_sites, according to Pliny’s descriptions and modern scientific analysis.
In the last days, we have been lucky enough to appreciate the pictures of this thermopolium at @pompeii_sites, including the loose brushstrokes and the vibrant yellow background. If you want to know which pigments Romans used, keep up with this #thread. https://twitter.com/pompei79/status/1342797070118367234
In case you are interested in how fresco paintings were executed at @Pompeii_sites, you may find this #thread helpful: https://twitter.com/cinnabarim/status/1264587203654672384
The conservation state and the brilliancy of the yellow used in the thermopolium paintings are mind-blowing, but there are further examples at @pompeii_sites in which a bright yellow hue was used. https://twitter.com/Carla_Ardis/status/1296900628309061633
Next to the yellow stripe of the oecus of the Villa di Poppea, a very bright yellow was also applied in the background of these portraits of Egyptian deities at the Black Room of Boscotrecase. https://twitter.com/DrJEBall/status/1296776852103729153
Yet, yellow was not only used in geometrical backgrounds but also in garments and other details, as can be observed in the well-known paintings of the Villa dei Misteri at @pompeii_sites. https://twitter.com/DocCrom/status/1299257620835061767
Yellow was also employed in the robe of this *never-enough-appreciated* cupid seller, found at the Villa Arianna of Stabiae. The pictorial layer losses could point out to the use of a secco technique to apply the pigments with an organic binder. https://twitter.com/pompei79/status/1173590019900133378
For more insights into the combination of the secco technique with fresco painting, check this previous #thread: https://twitter.com/cinnabarim/status/1325482624761155584
Yellow was of course used in Roman mural paintings executed in different places other than the Vesuvian area, as the Villa della Farnesina in Rome. It was used again both in background patterns… https://twitter.com/understandrome/status/1083029206374797312
…and in figurative details, such as the golden throne of this delightful portrait of Venus. https://twitter.com/DemosthenesXIV/status/1198298018837155840
According to Pliny, “sil” is a kind of slime or soil, found close to gold and silver mines that matches with our yellow ochre. The best one was the Attic "sil", which could cost up to 2 denarii per pound, while marbled "sil" only costed 1.
Other "sil" varieties were those of the Isle of Scyros and Achaia, used for shadow-painting and sold at 2 sesterces per pound. Finally, Gaul "sil" costed 2 asses less per pound and was used for painting strong lights, while marbled "sil" was employed in backgrounds.
Thanks to Pliny, we even know that the Greek painters Polygnotus and Micon were the first to employ "sil" in paintings. It is always noteworthy to appreciate that our dear Polygnotus was the first to accomplish many things, as described in this #thread: https://twitter.com/cinnabarim/status/1281962388552589313
Pliny also mentions another type of yellow pigment, the mineral orpiment or “auripigmentum”, mined in Syria and melted by Caligula in large quantities with the hope of obtaining real gold. https://twitter.com/LapworthMuseum/status/1092392612676415493
However, Pliny did not encourage the use of orpiment in wet media, such as fresco painting. It has indeed been detected in Egyptian polychromed wooden artifacts of the Greco-Roman period.
https://zenodo.org/record/3746942#.X-tP0thKjIU
https://www.tandfonline.com/doi/abs/10.1179/sic.2003.48.1.41
https://zenodo.org/record/3746942#.X-tP0thKjIU
https://www.tandfonline.com/doi/abs/10.1179/sic.2003.48.1.41
In the analysis of Pompeian pigments goethite (FeOOH) has been found as main component of yellow ochre or “sil”, often mixed with quartz, carbonates, kaolinite, or leucite. These impurities, together with jarosite, suggest the use of local volcanic clay. https://twitter.com/cinnabarim/status/1263151414366388229
Observed under the microscope, the original Pompeian pigment presents tiny blue and green particles that correspond to #EgyptianBlue and malachite, probably due to contamination of the yellow pigment.
https://www.sciencedirect.com/science/article/pii/S0026265X17308536
https://www.sciencedirect.com/science/article/pii/S0026265X17308536
It is curious to note that one of the yellow pigments analysed at the Temple of Venus at @pompeii_sites was prepared by directly grinding a trachyandesitic-phonotephritic volcanic glass, although this has not been recorded in other paintings. https://www.sciencedirect.com/science/article/pii/S0305440311001816
Taking into account that the most ubiquitous yellow in @pompeii_sites is based on an oxyhydroxide, its dehydration into red iron oxide at high temperatures due to the eruption happened very often. Hence, the original yellow hue is no longer visible. https://twitter.com/ZeeshanJaanam/status/1298203017980850176
We addressed this topic in a previous #thread about the pigments of @pompeii_sites: https://twitter.com/cinnabarim/status/1263151377695625217
To finish this #thread on yellow hues at @pompeii_sites I would like to draw your attention to this fact: Pompeian paintings have always looked so vivid when freshly excavated. It is our responsibility to care for their conservation for future generations. https://twitter.com/cinnabarim/status/1338145165949726724
Aquí te cuento este #hilo en castellano: https://twitter.com/cinnabarim/status/1344001307871490049
