The inscription band between the smaller columns reads 'Allah'. That between the larger columns is inscribed 'sovreignty belongs to God, the One, the Victorious'. The outer inscription band contains the first sura of the Qur'an, fatiha. It has not proved possible to read fully the cursory inscription around the arch itself.
The composition of the mihrab has a typical concentric emphasis, the smaller central arch mirroring in form the larger framing arch. Also typical is the combination of both naskh and kufic scripts, the kufic forming a purely decorative band around the inner arch. The most unusual feature of the present lot is the form of the two arches themselves. On most mihrabs the arches are comprised of four straight lines, the lower two being vertical, the upper forming a triangular pediment. On occasions, a more rounded form is used, but the horseshoe form seen here, recalling an early architectural form, is very rare. The lamp contained within the upper arch is part of the restoration; originally it would almost certainly have been a palmette. For a range of Kashan blue and lustre mihrabs dating from the 13th-15th centuries, see Watson, O.: Persian Lustre Ware, London, 1985, pp.122-149.