Corvidae Antique has dated this piece to the 1910s.
You can find examples which originate later into the 20th century but they are often less well defined and cast in pewter rather than silver.

The brooch is not signed; we've seen this design attributed separately to Marius Hammer and Astri Holthe, it's certainly the work of a fantastic Norwegian jeweller!
SIZE: Approximately 4cm diameter.
WEIGHT: 15.7g.
MATERIALS: 830 silver.
HALLMARKS/STAMPS: Stamped 830S.
CONDITION: Excellent antique condition.
ERA: Estimated Arts and Crafts, c. 1880s-1910.
Corvidae Antique has dated this piece to the 1910s.
Hand picked jewellery from a friendly family business
You can view the stock and full dealer information on the Corvidae Antique Profile Page