The Friday Mosque, Isfahan, Iran, 12th century
The ceiling of an Iwan is made of piled brick in three-dimensional form.
The Muqarnas was a powerful formation in the early stages,
expressing the transmission of structural stress.

The Royal Mosque (Imam's Mosque), Isfahan, Iran, 1612 -30
At Iwans in the 17th century, Muqarnas became a technique of superficial
ornamentation, suspending intricate gypsum panels finished with faience tiles.

The Iwan of the Harun Velayat Mausoleum, Isfahan, Iran
Looking at a Muqarnas ceiling under repair,one can recognize
that it is a cosmetic structure intented only for decoration.
Tiled gypsum panels are hung from the true brick dome.