Minecraft wiki entry for Explorer_Map, associated text: The basic functions of a buried treasure explorer map are similar to that of the other two. However, instead of showing the structure icon on the map, it shows a red X instead. The buried treasure structure is located on the same X and Z coordinates as the middle of the X (the player marker may need to be aligned with the bottom of the middle 2×2 pixel square of the X). To locate the chest spot, hold the treasure map with both hands, not in the offhand slot.