The tomb, or gunbad, was built for Amir Shams ad-din Qarasunqur, a former Mamluk slave who served as the governor of Maragha until his death in 1328. It consists of a square brick chamber raised on a stone base containing a crypt. The inner and outer domes have not survived. The entry, which faces north, was originally accessed with a set of steps that are now missing. The entrance to the crypt is located on the east side. This tomb bears close resemblance to Gunbad-i Surkh, an earlier tomb also located in Maragha.
The use of faience for exterior decoration, also seen at the Tomb of Mu'mina Khatun in Nakhchivan and at Gunbad-i Surkh, is a major decorative element at the Gunbad-i Ghaffariya. Four engaged columns woven with diagonal brick pattern and decorated with mosaic faience articulate the four corners of the monument. The exterior decoration is focused on the entry façade, which bears an inscriptive panel dating the monument to the reign of Sultan Abu Sa'id Bahadur Khan's reign. A wide decorative band composed of interlocking stars and pentagons, frames the recessed doorway and its muqarnas crown. Flanking the entryway are two narrow niches with pointed arches; their surfaces are carved with geometric patterns. Faience has been used extensively on the muqarnas crown and the inscription, and to highlight the geometric carvings of the entry façade.
The two side and the back walls of the monument are identically divided into two halves with shallow arched niches. Above each niche is a rectangular panel that bears traces of the original plaster molding. The spandrels of the arches are decorated with faience. Placed at the center of each niche is a miniature panel, also composed of a shallow niche topped by a rectangle. It is within these miniature panels that the heraldic sign of Amir Shams ad-din Qarasunqur, in the form of two inverted Js, is inscribed. The cornice and faience decoration were partially restored by Mirath-i Farhangi, an organization in charge of cultural affairs in Iran.
Inside, the monument is decorated with a series of arched panels. There is a mihrab niche at the center of the southern wall. The plastered walls bear traces of painted decoration.