Meiji 19th Century Quail Shakudo Brooch In Gold And Silver

This unusual round brooch is made of mixed Japanese metals, covered with a very thin gold plate and mounted in silver. The design depicts two quails in a naturalistic setting of wildflowers. The appliqués are in copper and silver with gold details.
On the back is a signature in characters that Google translates as "zhengchen," the meaning of which is uncertain. The brooch mechanism has a hinged pin and tube, and a C-shaped clasp, and is fully functional.

Note: some minor wear, a few small dents near the prongs securing the silver mount, and two holes in the gold plate on the back of the brooch, indicating that this brooch was likely originally mounted as a button.

Tested with a 14-karat touchstone for the thin gold leaf and silver for the mount.

Very good condition, Japan, Meiji period, 19th century, circa 1880.

Diameter 3.3 cm,
Weight 17 g