Minecraft wiki entry for Diamonds, associated text: To locate diamond ore by caving, simply explore any cave, either by locating surface entrances or digging and working down to level 15 or lower. In Java Edition, pressing F3 (the debug screen) helps check depth. In Bedrock Edition, there is a "show coordinates" game setting that doesn't count as a cheat. It is best to mine at level 11 or 12 because lava beds mainly spawn at level 10. A bucket of water can be useful to stop lava flows.