That's a trick with language-dependent results, which might be appropriate for some magic (e.g. command) but seems counterintuitive for this one. Some languages, like English and German, have a lot of specific nouns for specific things. If I can't search for a "lead box", I can search for a "safe". Other languages, like Mandarin, make much more extensive use of adjectival phrases. I don't know if Mandarin happens to have a specific word for "safe", but given what I do know of the language it would not surprise me in the slightest if the phrase they used was in fact "lead box" or something similar. (EDIT: Looks like it's "risk protection box".)See, I think I'd rule that they could use the spell to search for something that is described as a noun, only. Necklace, not silver necklace. Box, not lead box. That sort of thing. Although maybe that becomes too limiting . . .
Given how easy it is to foil the spell, I'm comfortable letting the spell work on any object which can be uniquely identified.
Seriously, a thousand feet? The only time a lich should ever be within a mile of its phylactery is when it has just rejuvenated, at which point their first order of business is to teleport away so that nobody sees them leaving.