The near-black surface of Florence’s Etruscan orator was made deliberately, a new analysis finds

The dark, almost black skin of the Arringatore, the life-size bronze Etruscan orator in the National Archaeological Museum of Florence, was a finish someone chose to create, according to a team of Italian conservation scientists. Their analysis found a two-layer copper oxide crust of cuprite and tenorite, which the authors read as the product of controlled heating of the surface. Visitors have long assumed the colour was simply centuries of decay.

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The statue shows Aule Meteli, an Etruscan citizen in a toga with one arm raised, and stands about 179 centimetres tall. Workers digging at Pila near Perugia unearthed it in July 1567.

The colour has been a puzzle for a long time because accounts of the discovery say the bronze was green when it came out of the ground, as Archaeology magazine notes. The usual assumption was that the surface had darkened afterwards through natural corrosion and later coatings. The new paper tests that assumption directly by reading the chemistry of the surface layers rather than judging by eye, and it uses the cleaned areas exposed in the most recent restoration to do so.

Cuprite and tenorite: the two-layer crust

The work was led by Salvatore Siano of the Nello Carrara Institute of Applied Physics at Italy’s National Research Council in Sesto Fiorentino, with colleagues Iacopo Osticioli, Daniele Ciofini, Andrea Mencaglia, Lorenzo Marzini and Juri Agresti, plus Sonia Mugnaini and Marco Giamello of the University of Siena. Their paper in the journal Heritage reports a cuprite-tenorite bilayer on the surface. Tenorite is a black copper oxide; cuprite is a red one. The black sits on top, with the red beneath, and the authors say the pairing formed through thermally induced surface oxidation.

In the abstract the authors describe their result as the “first compositional and microstructural demonstration of an intentional blackish patina” on this bronze, and they place the statue in the late Etruscan period, which they call still little known. The wording is a claim about what the evidence supports for this object, not a statement that every dark Etruscan bronze was treated the same way.

LIBS, Raman and the other tools used

No single instrument settled the matter. The team combined laser-induced breakdown spectroscopy, known as LIBS, which fires tiny laser pulses to read how composition changes with depth, with micro-Raman spectroscopy, scanning electron microscopy with X-ray analysis, X-ray diffraction, infrared spectroscopy, microscopy of cross-sections and radiography. The LIBS depth profiles were taken at 38 sites and showed a leaded bronze averaging roughly 13.5 percent tin and 4.0 percent lead. Raman mapping confirmed that the tenorite layer is continuous across the sampled areas, according to the full text of the study.

Coverage by Archaeology magazine and Greek Reporter adds that conservators found smooth, nearly black patches on the face, hair, clothing and arm after a 2008 to 2009 restoration, and that the team examined 15 small samples from those areas. A dark brown coating applied in the 18th or 19th century had been removed during that restoration, which is what exposed the older surface underneath.

Why heated copper points to a deliberate finish

The argument rests on how the layers are built. The red cuprite layer partly reproduces the dendritic, tree-like microstructure of the original cast bronze, which suggests it grew by direct oxidation of the metal itself. The black tenorite formed in a later step on top of it. The researchers did find a greenish layer of secondary copper chlorides at the base of the tenorite, so burial left its own mark, but the continuous black crust above it fits a heating process better than soil chemistry, in their reading.

The authors also looked for signs that the darkening happened after excavation, such as heavy cleaning or burning that a later treatment would likely leave behind, and reported none, as Greek Reporter relays. That reasoning narrows the possibilities without closing them. The authors could not reconstruct the exact ancient recipe, including whether substances were added to the surface, so what is established is the chemistry and structure of the crust, while the intention behind it is an interpretation built on that evidence.

A black statue with red details

Other findings from the paper put the colour in context. X-ray imaging shows the statue was cast in eight separate pieces, hollow-walled and only a few millimetres thick, and joined with cast-on joints. A narrow stripe on the toga is made mostly of copper, giving it a reddish tone that would have stood out against a dark surface, and the eyes were originally inlaid with glass paste. Taken in that light, a dark patina looks less like an accident and more like part of a planned colour scheme, which is how the coverage describes the authors’ reading.

The date of the statue itself is the most widely accepted stylistic one, the second century BCE, according to the paper. That places the object in the late Etruscan world, and it is the period the authors say remains poorly understood. A deliberate surface treatment on a major votive bronze adds a small, concrete piece of workshop practice to that thin record, and it gives conservators a reason to look at other bronzes of the period for similar layers before older coatings are removed.

The study appears as Heritage, volume 9, issue 10, article 402, with the DOI 10.3390/heritage9100402.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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