Beautiful sparkly butterfly brooch with pearly/opalescent black enamel (or resin?) wings inlaid with cubic zirconia or rhinestones. The edges are lined with further stones.
Missing 2 stones from the wings. Looks like an easy repair.
Marked 925 on the back at the very bottom (see close-up). Could be used as a pendant using the loops on the back of the wings--it would then hang at approximately a 45 degree angle from the chain.
1" long