This 4th century Armillary Sphere Ring has been replicated many times in more than one country over the centuries.
Created by the Chinese astronomers Shi Shen and Gan De during the Han Dynasty in the 4th century, the ring (or armillary ) was replicated in the 2nd century by the Greek astronomer Eratosthenes.
The ring has evolved over time, now available in different materials that include wood (as it was originally), bone, stone, metal, glass, gemstone, and plastic. It may also be set with stones, such as diamonds, minerals, or glass.
Read more about the Armillary Sphere Ring here.
See more 4th Century works by various artists here.