This is a wonderful enamel brooch or pin made of enamel on copper in a boomerang shape, very mid-century atomic age!  The piece is unsigned but beautifully made, featuring raised blue “pebbles” against a blended green, yellow and white background.  The piece is quite large, measuring almost 4” in height (3 7/8”), measured straight across.  It is in very good condition with no chips, cracks or wear.  Beautiful pin in a larger than usual size - sure to be noticed!