Minecraft wiki entry for Ocean_Ruins, associated text: Cold ocean ruins are primarily composed of stone bricks and gravel, and also contain prismarine, sand, magma blocks, sea lanterns, polished granite, glazed terracotta, bricks, planks, cobblestone, mossy cobblestone, stone brick stairs, obsidian, and/or a chest with loot in it. Warm ocean ruins are primarily composed of sand and sandstone, and also contain polished granite, polished diorite, sea lanterns, magma blocks, gravel, terracotta, sandstone stairs, and/or a loot chest.