Caves
A cave is a naturally generated path through the underground rocks. Caves generate in both the overworld and the nether. Valuable ores can be found deep inside caves in the overworld like Coal ore, Iron ore, and in the deepest of caves, you can find Diamond ore. However, ores do not spawn in nether caves.
Contents
Patterns of generation
Flowing caves
The most common type of cave seems to be a carved pathway. They can range from only a few blocks wide, to being relatively massive in size. When generated, the caves will replace all blocks in its path with air, except for a select few, such as sandstone.
Cliff caves and overhangs
When a cliff is generated, there's a chance that the generator will spawn a cave at its base. The caves generated are usually small.
Caverns
Caverns in Mine Blocks are small reservoirs of |liquid (such as water, lava, and acid), found deeper underground.
Nether caves
Caves generated in the nether are much larger in width, length, and frequency, yet otherwise identical to the ones generated in the overworld. They account for much of the generation time for the nether.