The doors of the Basilica di San Marco: a scientific examination through MA-XRF

THE DOORS OF THE BASILICA DI SAN MARCO: A SCIENTIFIC
EXAMINATION THROUGH MA-XRF

S. Longo,1 R. Andolina,1 M. Botticelli,1 S. Bottura Scardina,1 F. Falcone,1 M. Fera,2 G.
Ghiara,3 C. Miliani,1 E. L. Ravan,1 F. P. Romano,1 M. Mödlinger4 and C. Caliri1

1Istituto di Scienze del Patrimonio Culturale del Consiglio Nazionale delle Ricerche (ISPC-CNR), Catania, Italy
2Institut fur Urgeschichte und Historische Archaologie, Universitat Wien, Vienna, Austria
3DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
4IMAREAL, Paris Lodron University Salzburg, Körnermarkt 13, 3500 Krems/Donau, Austria

This study focuses on the copper alloy doors of the Basilica di San Marco in Venice, renowned
for their artistic and historical value, with particular attention to their chemical composition,
production methods, and detailed inlays. Dating back to the 11th and 12th centuries, these doors
exemplify a blend of Byzantine, Gothic, and Renaissance styles, featuring decorative motifs,
biblical scenes, and depictions of saints, as well as the distinctive use of a variety of different
inlays. Macro X-ray Fluorescence (MA-XRF) analysis, carried out during the GAPAMET
MOLAB E-RHIS campaign, was employed to evaluate the elemental distribution and identify
key materials present across the doors. For the first time, this advanced MA-XRF technology
was utilized to reveal the elemental composition of the materials used as inlay on these historic
bronze doors, providing new insights into their manufacture. The analysis uncovered a broad
range of elements, including copper (Cu), silver (Ag), gold (Au), mercury (Hg), tin (Sn), lead
(Pb), and zinc (Zn), with notable compositional differences between the Main Door (MD) and
the San Clemente Door (SC). These variations imply that the doors were likely created in
separate workshops or at different times, possibly utilizing different alloys. The ability to
identify and map the distribution of these elements with high precision allows for a deeper
understanding of the materials and techniques used by the craftsmen of the time, shedding light
on the historical processes behind these iconic doors.