Green lightsaber

Someone may have already addressed this, but.... where did Luke's green lightsaber go? I don't remember him having it when he was sitting on the rock at the end (I don't wanna say too much, because Spoilers), Rey didn't touch it, Leia didn't have one at all during the film. In another thread, it was discussed that the blue lightsaber Kylo/Ben has in the flashbacks may have been a practice saber and not The Skywalker Lightsaber and Luke may have fashioned lightsabers for all his students, or taught them to make their own as a right of passage. However, Luke  was using his green lightsaber in that same flashback. So what happened to it? He actually doesn't seem to have one on Ach-too, although it could have been in a backpack or drawer someplace I suppose, or down in his X-Wing, and I think I saw it on his belt when he talks to the Force Ghost (again, avoiding spoilers in case anyone accidentally clicks on this and hasn't seen the film yet) about burning the tree, so that would make me think he had brought it with him, but I could have been mistaken and it could have just been a shiny piece on his belt. Not the best lit scene in the movie, and I did only see it once.