Commissioned by an Il-Khanid administrator from Oshtorjan and dated by two separate inscriptions to 1315-16, this mosque has survived in excellent condition. Construction appears to have been swift, executed in phases over a brief period. The decoration is of greater import than the primary structure, which consists of a narrow rectangular courtyard lined on three sides by arcaded prayer halls; on the fourth side, a vaulted iwan fronts a dome chamber. The main entrance portal with flanking cylindrical minarets is located on the northern exterior façade, off axis with the sanctuary - possibly due to constrictions of pre-existing structures.
The mosque is built with a mud brick core faced with fired brick. The dome chamber appears to have been erected slightly earlier, utilizing thick plaster over the mud brick core. The use of mud brick is unusual in the vicinity of Isfahan, where fired brick prevails.
The diversity of patterns, materials, and combination of materials employed in the decoration represent a compendium of decorative techniques from around the country. Exposed brick is found only in the arcades, although possibly this area originally had a plaster coat as is employed extensively in the rest of the structure. The plaster is carved in a variety of decorative designs, including geometric patterns; floral motifs in high relief; simulated brick bond, and brick end-plugs - in some areas arranged to configure rectangular kufic inscriptions. On the sanctuary walls and dome, traces indicate that plaster was painted in a vivid array of colors. The lofty stucco mihrab describes an uncommon proportion, reaching the zone of transition. Across the interior of the dome, decorative terracotta elements form eight radial ribs; diverse painted plaster patterns fill the interstices. The northern entrance portal is lavishly decorated with mosaic faience, glazed and unglazed terracotta.
An inscription on an eastern pier of the courtyard notes repairs undertaken in 1476 by a pious Oshtorjani, in the name of the Aq Qoyunlu ruler, Uzun Hasan.
Golombek, Lisa and Donald Wilber. The Timurid Architecture of Iran and Turan. Princeton, NJ: Princeton University Press, 1988.
Pope, Arthur Upham. "The Fourteenth Century." In A Survey of Persian Art from Prehistoric Times to the Present, edited by Pope, Arthur Upham and Phyllis Ackerman (assistant editor), Vol. 3 Architecture, Its Ornament, City Plans, Gardens, 3rd ed., 1079-1082. Tehran: Soroush Press, 1977.
Wilber, Donald N. The Architecture of Islamic Iran. New York: Greenwood Press, 1969.