Interesting topic, but do we really need three threads about the same news story?
To answer the OP's question, I'm pretty sure that if I tried to sell a stash of jewels like that someone would start asking questions, and I wouldn't know enough about jewelry to know if I was getting a fair price or not. Also, I wouldn't want the wrong people to know that I was sitting on $300K in jewelry. So I would probably hand the jewels over to the authorities and try to get some kind of finder's fee.