Keep Faking It
We have pointed out that some hiding spots are more obvious, at least to burglars. Why not use this to your advantage? If you have a bunch of customer jewelry laying around, now is its time to shine. You can fill a box up with this costume jewelry and find a better hiding spot for your expensive jewelry.
As this person points out, this would serve as the perfect decoy. Would it not enrage you if you got a box of costume jewelry but only realized it when you went to pawn it? The hope is that the thief would also be caught in the act of trying to pawn it, real justice if you ask me.