Minecraft wiki entry for Buried_Treasure, associated text: The treasure chest is almost always buried by some material. Most of the time the chest generates buried in a beach, so it has a sand or gravel block covering it. Sometimes, if generated on the side of an underwater hill, it spawns with stone blocks covering it. If it generates on the surface of the ocean floor, a gravel or sand block covers it. Nonetheless, terrain generation can cause the chest to be buried by any suitable terrain-generated blocks, such as coal ore and diorite.