I want to steal the diamond.  I don't care about the chip.  I will detach the chip and leave it inside the vault and then I will run away with the diamond.

Or perhaps you say that you attached the chip to the diamond very well, so I can't just detach it without damaging it.  That's annoying but I came prepared!  I have a diamond cutter!  I'll just slice off the part of the diamond that the chip is attached to and then I will steal the rest of the diamond.  Good enough for me :)