According to scholars, bronze mirrors first appeared in China during the Warring States Period and reached their height of popularity in Han and Tang times. During the Sung Dynasty mirror craftsmanship began to decline, and after the Yuan and Ming periods, because of the advent of glass, bronze mirrors slowly disappeared altogether.
The Tang era is considered the classical period of Chinese art, and historically, Tang mirrors are considered to have the highest artistic value. Artistic freedom was the norm and artisans broke through traditional stylistic conventions. On mirrors, in addition to the appearance of new shapes, reverse side buttons began to take on animal shapes and obverse surfaces became convex.
The bronze Tang mirror pictured here is 18.2 cm in diameter, 1.1 cm thick, and weighs 115 gm. It is edged with a water caltrop motif and the mirror surface is slightly convex. On the reverse side is a tortoise shaped button surrounded on four sides by lunar themes: "Chang O flies to the moon", a cassia tree, a jade hare, and a toad. The raised designs on the reverse side and silver-white color of the obverse are typical of Tang Dynasty mirrors.