And you suppose right. A few seem to have been discovered already, but there's no clue as to how many there are and it doesn't seem we're anywhere close to achieve it.

The "promised" [And he says it in a tone that shows how little he believes it.] way out is that by gathering the shards and rebuilding the ruby we get a wish and can use it to go back home. But we don't know if it works for everyone, if everyone has to make a wish or anything else