This is a stupendous piece that resembles a rhinestone glazed donut.  It is a three dimentional cushion of swirling rhinestones using three rows of varying sized rinestones overlapping in a swirl of glitter.  Set in a silver tone metal, each rhinestone is prong set.  This remarkable brooch is from the 1950s and is 2" in diameter and rises 7/8" from the surface. Two stones show some darkening due to age.

Side view: