This is a gorgeous antique stick pin; according to antique app Curio, it’s likely from Europe from the late Victorian or Edwardian era.

The vintage hat pin metal looks brass, perhaps gold filled but unsure; has some patina. This antique pin features a cluster of sparkling colorless stones that look like diamonds but are likely rhinestones or paste stones.

Looks very expensive and would look even more luxe with a good polish!