No. But an object can always be misplaced, lost, or stolen. It can be chosen not to be worn one day. It can be broken. It would be harder to trace a person, but to do so would mean a direct path rather than a possible dead end.

[Tohsaka answers quickly. If only because she already had this follow up prepared. If you're worried about losing a necklace, then track the necklace. If you're worried about losing the person wearing the necklace, then you better hope they actually put it on.]