On the picture: a detail of the mihrab (prayer niche In the center: the foot of the small column to the right of the niche. To its left: the (yellow) lit niche itself. To its right (and beneath it) some of the borders that frame the niche.
The niche is completely executed in glazed (and partly guilt) tiles. The tiles were locally produced, by artisans from Tabriz (Iran), under the supervision of Ali bin İlyas Ali, a ‘nakkaş’ (painter-designer) from Bursa, who had been sent to Samarkand by Timurlenk in 1402.

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Vakıf Abideler ve eski Eserler’ - Vakıflar Genel Müdürlüğü III, Ankara 1983