The walls round the massive first floor galleries of Hagia Sophia in Istanbul, and also right around the arcades underneath the galleries, are clad in panels of decorative stone, mostly marble, but many other multi-coloured and variegated stones as well. The decorators who constructed these panels often made the most of the pretty striations within the stone, reversing and adjoining panels cut from the same block to make a repeating pattern.
But, here’s the thing. As I was admiring this wonderful stonework, it suddenly occurred to me that to get the panels to line up the way they do, each panel would have to be very thin, probably only 1 0r 2 cm thick at most, or the pattern would change too much from panel to panel. So how did they do that in the 6th century AD? How can you slice very thin and totally flat panels one after another from a big block of stone – with NO power tools? No carborundum saws, no tungsten/diamond cutters, no lasers. By hand, but perfectly flat and straight and even. Eventually, I was so intrigued, I found someone to ask, and the answer astonished me.
Silk.
Twisted strands of silk-worm silk, when held taut and rubbed back and forth across stone, wet, is apparently strong enough and durable enough to cut through marble as if it was cheese. It takes a lot longer than slicing up a block of cheese, but it’s just as effective. How clever is that?
In the arcades that surround the massive central prayer space of the great dome Basilica of Hagia Sophia, the walls and pillars, and even the floors, are all clad in thin slices of variegated stone.
The upstairs galleries of Hagia Sophia also have marble-lined decorative walls.
This marble pattern has been created by cutting and then reversing each alternate slice from a single block of marble.
Many other types of stone have also been sliced and mounted on the walls. The central purple stone in this picture is porphyry. Purple was a colour reserved only for emperors, so this stone was usually only used for imperial sculptures or for decorating imperial palaces, but this great church was commissioned by the Emperor Justinian, so he would have approved of its use here.
Some very dramatic patterns can be constructed when the contrasting colours and striations within the stone are so pronounced.
Alternating panels of blotchy blue-green and cream-purple stones, with a feature strip of swirly stripes.
The facade of St Mark’s Cathedral in Venice is decorated with similar panels of multi-coloured stone, many of which were stolen from this church in 1204 AD during the disgraceful 4th Crusade. In some places inside Hagia Sophia, later restoration efforts have replaced some of the missing panels with painted facsimiles, trompe l’oeil illusions that are so well done they are quite hard to pick until you get very close.
Enthusiastical 