Woodbridge Antiques has dated this piece to the 1920s.
On the back there is a good fastening pin that works well and here the mark for David Andersen is very clearly visible along with the words ' Norway Sterling 925 S '(this particular style of mark was used from 1925).

Superb brooch in wonderful condition - great for a collector of David Andersen jewellery!
Marked: David Andersen Norway Sterling 925S
Measurements: Height: 2.6 cm Width: 2.8 cm Weight: 6.2 grams
Weights and measurements are approximate.
NJL35566
Woodbridge Antiques has dated this piece to the 1920s.
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