Antique Enamel/Cloisonné Clip & Sterling Chain

From my great great uncle’s estate: Approximately 1/2” diameter enamel or cloisonné spring clip that I’ve always worn on this 19” sterling antique chain. Spring is incredibly strong ( perhaps for a tie? ). Base metal is either copper or bronze. Cloisonné is in good condition with 2 small sections at ends degraded. Chain is marked “sterling” on the back of the intricate clasp.