Can I pawn collateral?

Someone owes me 3 grand plus 660 interest, I have some of their jewelry for collateral. It was a spoken agreement with witnesses, did not get a notary although we were supposed to. The due date to be paid back ped almost two weeks ago, I desperately need the money. I've heard they don't have the money and I can't get in contact with them. Is it legal for me to pawn the jewelry in the mean time until they pay me back ?