Barter
I'll come by and take a look. I couldn't tell a modern fake, but I know the tricks for the old ones. For pearls, if you rub them across your teeth and you feel grit, they're real. If they feel smooth, they're fake. And you can tell a rhinestone by the metal coating on the underside. It'll scratch off with a pin. If there are a lot of stones in the broach, it might be easier to take them out and fence them individually. Most people around here just don't have the money to buy a piece like that. But I'll talk to the Piccadilly Circus girls. I know they get a lot of gifts. And i'm cute and non-threatening, so they'll talk to me.
But yeah, I'll fence it for you. Might need to borrow Steve for the exchange.