Metal alloy brooch from the American firm Napier (you can see the brand on the back, although it is a little smudged by the passage of time)
Around 60 7.5cm long x 2cm wide
It may have normal signs of use such as some superficial micro scratches on the metal (see images)
The metal is NOT gold or silver so it can cause allergies if it comes into contact with the skin.
The images are part of the description