This is a Lovely Vintage Sterling Silver Swirl Leaf Brooch with 6 Nicely matched Japanese Akoya Cultured Pearls. You can use it as a Pendant as well(with your own chain.)
The Brooch measures 1 7/8" x 1" and is marked STERLING. I can't see a signature as to a maker, although it is in the style of Mikimoto; perhaps not as well made(I can see some glue at base of a couple of pearls at the stick.) It is a Very Lovely Sterling Silver Akoya Pearl Brooch/Pendant.
Sterling Silver Akoya Pearl Brooch