Brooch, pendant, old, cameo. AMCO is a jewelry brand, founded in 1919, in the United States. Brooch with pendant system, retractable in gold plated set with a shell cameo (We can see a signature.) point dimensions of the cameo. Approximately 2.8 cm by 2 cm. Weight 4.49g. Dimensions are taken approximately. The pin is not gold plated. Very good vintage condition.