Norwegian silver and blue enamel butterfly brooch 1950s

A vintage solid silver and sky blue brooch of a large butterfly motif with pointed wings and radiating guilloche design under light blue enamel and black body all with a gold wash and a roll-over clasp to the pin at the back - marked for David Andersen of Oslo - total weight 10.3grms - overall dimensions 54 x 29mm - c.1950 Norway