Butterfly Brooch Orange Enamel Rare CG Hallberg Guilloche 1921 Sterling Silver Stockholm A very Rare Guilloche Enamel Butterfly Brooch/pin from **CG HALLBERG. Gorgeous Orange and Black Butterfly with black body and sterling antenna. There is a little gradation to the colors, original to the pin. It Is Marked HALLBERG, and hallmarked for Stockholm, Sterling and 1921. It has a simple C and Hinge pin clasp. Measures 7/8 x 5/8.