This is a Coro rhinestone "cage" pin which one held two dress clips. It looks like there are stones missing, but they are all there.
The stones have darkened with age. These will not come cleaner or brighter. You should never soak rhinestone jewelry! This would be fabulous on a purse or headband for that next Gatsby party. Slip a feather through it! It measures 2 1/4" long. Signed Coro faintly on the back.