Diamond in Subnautica is usually found by breaking Shale Outcrops , which can appear in several biomes. Good early spots include the Mushroom Forest , Mountains / Mountain Island , Jellyshroom Caves , and Underwater Islands.

Best places

  • Mushroom Forests : one of the easiest early-game areas to search.
  • Mountain Island / Mountains : often recommended because Shale Outcrops are common there.
  • Jellyshroom Caves : a solid mid-game option if you can reach the depth safely.
  • Lost River / deeper biomes : can also contain diamonds, but they’re more dangerous to explore.

Quick tips

  • Scan rocky seafloor and cave walls for Shale Outcrops.
  • Bring a Seaglide and enough oxygen for longer dives.
  • If you’re early in the game, avoid very deep or predator-heavy zones until you’re prepared.

Fast answer

If you want the best early-game bet , head to the Mushroom Forest or the Mountain Island and look for Shale Outcrops.

If you want, I can also give you the safest diamond route from your lifepod.