Vintage/antique paste button, with clear glass paste stones claw-set in a diamond arrangement inside a circle. Brass back and U-shaped shank. Possibly converted from a broach as there are marks on the back rim, where fixings may once have been. There is also one stone which looks slightly smaller, so probably a replacement. This is how I found it - and whatever its history, now a very pretty sparkly button.

Size 1.1” (2.8 cm)