An ancient mosaic depicting Alexander the Great, estimated to be around 2,100 years old, is under analysis for restoration by researchers from the University of Naples Federico II in collaboration with the Museo Nazionale Archeologico in Naples (MANN), Italy. The artwork, known as the Alexander Mosaic, is housed in MANN and is believed to be a Roman copy of an earlier Hellenistic painting by Philoxenus of Eretria.
Historical Context and Artistic Significance
The mosaic captures a dramatic scene from the Battle of Issus in 333 BCE, where Alexander the Great’s forces clashed with the Persian king Darius III. Though historical accounts of the battle’s troop numbers are often exaggerated, the encounter marked a significant victory for Alexander and solidified his legendary status.
Constructed around 200 years after the battle, the mosaic measures 5.82 x 3.13 meters and consists of over 1.9 million tiles. These tiles, none larger than 4 mm, were laid using the opus vermiculatum technique, creating a vivid depiction of Alexander leading a charge against the Persians.
Scientific Analysis for Preservation
Researchers employed non-invasive techniques to assess the mosaic’s state and gather data for its restoration. Methods included multispectral imaging, which revealed the vibrant colors, surface degradation signs, and previous treatment evidence. Portable X-ray fluorescence mapped the elemental composition of tiles, while Fourier transform infrared and Raman spectroscopy identified mineral contents.
Infrared thermography scanned key sections for thermal anomalies, and optical microscopy provided detailed imagery of the tiles and mortar. Endoscopic examinations unveiled structural features and materials used in past restoration efforts.
Findings and Future Restoration
The analysis revealed the presence of gypsum, wax coatings, and calcium oxalate on surfaces. Wax, likely applied during 19th-century restorations, and gypsum traces from protective layers during the 1843 relocation to MANN were identified. The tiles were categorized by composition, with carbonate-based and silicate-based tiles, as well as some with glassy compositions.
Further analyses are planned, focusing on mortar samples and additional imaging to support structural reinforcement efforts for the mosaic’s future conservation.
The study, “From tiny to immense: Geological spotlight on the Alexander Mosaic (National Archaeological Museum of Naples, Italy) using non-invasive in situ analyses,” offers insight into the mosaic’s complex composition and preservation challenges, guiding restoration endeavors.