A finial is the "crowning decoration of a dome." 1 Humayun's Tomb's dome's finial's 18-foot tall gilded form is made of brass around a wooden core.2 Its design is comprised of stacked disc shapes alternated with pot shapes underneath a shahada inscription.
1. Margaret S. Graves and Benoît JunodAga, eds., Architecture in Islamic Arts: Treasures of the Aga Khan Museum (Geneva: Aga Khan Trust for Culture, 2011), 350.
2. "Finial Documentation," Nizamuddin Renewal, accessed May 1, 2020.
Hillenbrand, Robert. "Splendour and Austerity: Islamic Architectural Ornament." Annual Halt, no. 2 (1995): 8-27.