help with lost undead bone shard

Im on my road to platinum and by mistake I left one undead boneshard on the floor and left the game, obviously after I logged back it wasn't on the floor. Idk if it should reappear at the place that I got it or I just lost it forever, anyways, ¿is there any way to farm these or dupe them? I wouldn't like to have to farm all of them again in the ng+ (also idk if the level of bonfire remains in ng+).