Antique Iris Brooch—Gold Over Silver

This three-dimensional brooch, depicting an Iris with folding petals, has a copper and green patina. 

Dimensions: 2.5" long x 2" wide x 1.2" thick
Markings: 1/20 12K G.F. ON SILVER with Makers Mark
Material: Gold filled over silver
Period: 1940‘s or earlier
Weight: 9.7 grams
Condition: 8 (excellent working condition, no damage showing anywhere, patina shows on both sides)