REVETMENTS
There is evidence of marble revetments in Christian places of worship as early as the 3rd century (the popes' cubicle in the catacombs of St. Callistus); then, with the triumph of the Church, marble, specially worked or more often taken from other monuments, was frequently used as revetment inside sacred buildings, while externally it was limited to the decoration of individual architectural elements.
In the Constantinian period, the use of inlaying walls with polychrome marble panels was introduced, not only with architectural partitions and ornaments, but also with complex figurations; the prime example being the civil basilica of Junius Bassus (317), known through the drawings of G. da Sangallo and of whose ornaments fragments remain in the Capitoline Museum. This technique was employed in religious buildings of the second half of the 4th century (the Ursian Basilica in Ravenna and the original Ambrosian Basilica in Milan), as can be inferred from descriptions and the few surviving remains, reducing the ornaments to simple symbolic representations; finally, in the 5th century, it was reduced to geometric motifs exploiting the polychromy of materials (St. Sabina in Rome). The tendency toward decorative abstraction is accentuated in the wall architecture of St. Vitalis in Ravenna and the cathedral of Parenzo; subsequently, while this technique in Italy gave way to painted decoration, it developed and perfected in the East, reaching its highest expression in Hagia Sophia in Constantinople.
In Romanesque architecture, following the model of St. John’s in Florence, marble revetment was limited to only two colors, with the intention of enhancing spatial relationships, sometimes even outlining architectural motifs: the most notable example is in the basilica of St. Miniatus al Monte, where the decoration marks the spatial rhythm of the façade. In Sicily, too, marble revetment, though combined with terracotta, contributes to highlighting architectural lines (the bell tower of the Martorana, the cathedral of Monreale). In Gothic architecture, on the other hand, marble revetment generally has no connection with the structural system (the flank of the cathedral of Perugia, St. Mary of Collemaggio in L’Aquila, St. Mary Novella in Florence).
Even in the early Lombard Renaissance, intarsia revetments presented a purely decorative character independent of architecture (e.g., the Charterhouse of Pavia, where Candoglia white, Valcamonica red, and Cira green are combined; the Colleoni Chapel in Bergamo in white, red, and yellow); but in Venice, in Santa Maria dei Miracoli, Lombard craftsmen gave marble revetment an architectural value once more, making this church perhaps the most typical example of the Renaissance. Later, a search for funereal solemnity is seen in the calculated setting of porphyry panels within white frames between black colonnettes in the Gondi Chapel in Santa Maria Novella by G. da Sangallo. At the beginning of the 16th century, any search for polychromatic effects on the exteriors of churches ceased; projects for marble façade revetments left rough from earlier periods were abandoned at the outset, so foreign were they to the new taste (St. Petronius in Bologna, the cathedral of Reggio Emilia). Even the Baroque excluded polychromy on façades, while accentuating the splendor of colored marbles inside, no longer in minute designs but with applications over large surfaces (Santa Maria della Vittoria, Gesù e Maria in Rome, Corpus Domini and St. Lawrence in Turin; St. Philip Neri in Naples).
The conception of the chapel as a self-contained architectural organism allowed marble revetment to be limited to one or a few areas of the church: the first examples date to the early 1500s (the Chigi Chapel in Santa Maria del Popolo in Rome) and reached their greatest decorative richness in the following century in the Chapel of the Princes attached to San Lorenzo in Florence, entirely clad in rare marbles, hard stones, gems, and gilded bronzes, with effects of great splendor but mediocre taste; of greater elegance is the Chapel of the Monte di Pietà in Rome, sumptuously clad in precious marbles, alabasters, and Sicilian diaspore. A typical expression of late Baroque is seen in the Cybo Chapel in Santa Maria del Popolo in Rome, where polychromy imparts a character of severity, while in the Chapel of the Holy Shroud in the cathedral of Turin an even more solemn effect derives from the commitment to parietal revetment in only black marble. The preference accorded in the 18th century to stucco limited the use of marble revetments in central and northern Italy; whereas in the south of the peninsula and in Sicily their use continued intensively until the end of the century. The last great application of marble in church revetment is found in the nave of the Gesù in Rome at the beginning of the 19th century. In the same century, however, it was adopted in completing façades left in a rough state, using marbles of colors harmonizing with the rest of the building. Thus for the cathedral of Florence, Carrara marble, Prato green, and Maremma red were employed; for that of Grosseto, alternating bands of white marble and Gualdana red; for Santa Croce in Florence, only Carrara marble.
In our own century, marble revetments are generally limited to individual chapels, such as that of the Sacrament in San Carlo al Corso in Rome, redone for the priestly jubilee of Pius XI, and another, even more recent, in Sant’Andrea delle Fratte, also in Rome; an example of the extension of marble revetment to the entire interior of a church is found, still in Rome, in the church of the Most Holy Addolorata.
The use of wood as wall revetment is quite rare: a characteristic example is the hall of the College of the Mercanzia in Perugia, decorated with geometric motifs. Sometimes, however, revetment extends only to limited stretches of wall, especially above the stringcourse (Saints Severinus and Sossius in Naples, the cathedral of Pisa). Even rarer for wall revetment is the use of leather, of Eastern derivation, sometimes employed in the 17th century in secular buildings, and entirely excluded from religious ones.
— See plate LVI.