Abstract

Persian Islamic architecture has always shared an inseparable bond with sacred arts, particularly tilework. In this context, dadoes—positioned at the observer's eye level—serve a dual purpose: providing structural stability and offering a premium canvas for the most delicate artistic ornaments. The problem statement of this research is based on the premise that while the geometric "eight-pointed star" pattern is preserved in the dadoes of two prominent monuments in Mashhad—the Holy Shrine of Imam Reza (AS) and the Khwaja Rabi Mausoleum—the chronological gap between them (Ilkhanid-Timurid era vs. Safavid era) has led to fundamental shifts in visual systems and construction technologies. This study seeks to explain the geometric differences, construction techniques, and how the technological transition (from luster to haft-rang/seven-colored tiles) influenced mathematical proportions and the visual reading of motifs and inscriptions. The research methodology is descriptive-analytical with a comparative approach. Data were gathered through library research and field studies, including direct observation and visual documentation of selected samples from the Astan Quds Museum (related to the Shrine) and the dadoes of the Khwaja Rabi Mausoleum. Data analysis was conducted using visual content analysis to extract structural and visual characteristics into comparative tables. The findings indicate that during the Ilkhanid period, tiles were viewed as "sacred objects" and independent artworks with miniature details. Conversely, in the Safavid era, the haft-rang technique replaced the costly luster tiles to cover larger surfaces in less time. Construction technology shifted from luster toward haft-rang and mosaic techniques, and the color palette evolved from dignified golden-brown tones toward vibrant, brilliant colors with sharp contrasts. Furthermore, compared to the Ilkhanid delicacies, Safavid motifs became larger and bolder to ensure better legibility for observers from a distance.