Those who have been to St. Peter’s Basilica or have seen pictures of its impressive interior have likely marveled at the beautiful images that are above each of the many side altars. Some of them are quite famous images as well, such as the Transfiguration by Raphael, pictured below. But did you know that none of them are paintings?
Maybe you’ve seen before – perhaps in an old church – a painting that was darkened with age, probably due to things like the candle smoke, incense, general pollutants in the air, etc. In order to avoid having this happen in St. Peter’s, all of the altarpieces are mosaics! Except one. The altar in the great Blessed Sacrament chapel has a very large painting behind/above it (and it is somewhat darkened, as well); photography is not allowed in there, so I don’t have a photo to share with you.
Looking at the above image of the Transfiguration, you might never guess that is a mosaic, given how finely crafted it is. Thousands of little pieces of glass in all different colors were assembled to make this beautiful reproduction, and so many others throughout the Basilica. In fact, there is a mosaic workshop in the Vatican that produces (and conserves/repairs) all of these mosaics. And over time, if they start to get a film on them, they can simply be wiped clean.
The original of Raphael’s Transfiguration is in the Vatican Museum, and is well worth seeing, by the way!