Barbara Brend described as follows: "the turquoise cable moudling of an arch is seen below the dome, in which concentric rings of thirty-two lozenges diminish in size as they approach a centre which gives an impression of luminosity. The design, which suggests both movement and stillness, is a powerful though not an explicit vehicle of religious symbolism, speaking of the harmony of the universe. ... The support system of dome is illustrated by eight great arches of turquoise tilework in cable form which rise from a low dado to the full height of the wall, four in the position of squinches and four against the side walls; between them are kite-shaped squinches-pendentives. Within the dome, ranks of units of tilework of ogee-mandorla form are set in a lattice of plain brick and diminish in size until they meet a central sunbrust patterned with a tracery of arabesque".