Headstone with an angel-figure with four wings holding a Cross-on-the-Lotus symbol. Photo by Gustave Ecke c. 1927 via Macquarie University.
From the source:
The best photograph of this stone was taken by the art historian Gustave Ecke c. 1927 which he found preserved in a local Daoist temple in Quanzhou.
(…) Nestorianism reached China in the 7th Century CE from the Sassanian Persian Empire via the Silk Road. The migration was intensified as a result of the conquest of the Sassanians by the Arabs in the following century. The religion was given permission by imperial court for diffusion as early as AD 638 and was first called “the Persian Religion (or Doctrine)” (Bosijiao) because of its long connection with Sassanian Persia.