What materials and decorative features were used inside Hagia Sophia?

The interior of the Hagia Sophia is renowned for its lavish use of high-quality materials and intricate decorative elements that reflect its history as both a Christian cathedral and an Islamic mosque.1

Materials

The structure is defined by its extensive use of marble. The columns were selected for their variety and color, while the lower portions of the walls are lined with marble slabs. The building also features stone and brick construction, which is characteristic of the Byzantine tradition.12

Decorative Features

• Mosaics: Historically, the upper walls and roof were adorned with elaborate mosaics. These featured strong, clear tints and techniques such as the tilting of tesserae and the use of gold and silver cubes to manipulate light.1
• Carvings: The interior contains elaborately carved cornices and capitals.1
• Islamic Additions: Following the 1453 conquest, several features were added to align the space with Islamic tradition, including a mihrab (a niche indicating the direction of Mecca), a minbar (pulpit), and a large chandelier.13