Very pretty! Antique brass, with a fancy cutout star design. And a nice small size; small enough to be a cake plate in a tiny tea scene. No hanging loop, but there are open spaces in the decorative edging you could slip a jump ring through.
Shown below with 2 more small round filigrees for relative size. Left to
right: 27mm Round Filigree Setting, 21mm Fancy Round Filigree and a
filigree only sold as part of the Alice in an Altoids Tin Kit.