Welcome to t-net! Your first find sure looks good! The small circles within the large circle probably originally all had stones in them, maybe gemstones or maybe fakes. The item as a whole seems to be a brooch, though I'm no expert in anything. Have fun hunting for more good stuff! Andi
Nokta FoRs Gold, a Gold Cube, 2 Keene Sluices and Lord only knows how many pans....not to mention a load of other gear my wife still doesn't know about!