a large flat brooch of a goldfish, by the Hmong people or other nearby south asian tribe.
has a couple chains with little charms hanging off the lower fins. 
simple bar pin & safety clasp soldered onto the back. 
judging by the brooch pin and the chains, it is only vintage and probably a souvenir, not antique. 

tests as a low grade silver, somewhere between 25 to 50%. 
quite large, about 5.25 total length, slightly over 3" across from mouth to tail.