Sulfur in Subnautica 2 shows up as bright yellow crystals clustered around lava geysers, which means the bulk of it sits in scalding water that will cook an unprotected diver. Before you can mine the big deposits, you need the heat tolerance adaptation. There is, however, a small early-game stash you can grab without it.
What sulfur is used for
Sulfur feeds into two important early-to-mid crafting paths: strong acids and advanced wiring kits. Those unlock further tech progression, so once you can reach the lava biome safely, a single farming run sets you up for a long stretch of building.
Sulfur looks similar to salt at a glance, just yellow instead of white. Loose pieces sit on rocks and coral structures, while the larger nodes need the sonic resonator to break open.
Unlocking heat tolerance
Heat tolerance is the third adaptation you receive, after pressure tolerance and digestion. You earn it through the main story by following signals and interacting with blackboxes.
Step 1: Progress the story until you craft the sonic resonator. You'll need it to break harder deposits and to open story gates further out.
Step 2: Use the sonic resonator to reach the Wander Blackbox and cure the Angel Comb located there. This is the milestone tied to the heat upgrade.
Step 3: Place your hand on the Angel Comb after the cure. Heat tolerance unlocks immediately, letting you survive the lava region's ambient damage long enough to mine.
Early sulfur before heat tolerance
If you need a couple of pieces before unlocking the adaptation, head to Chap's Blackbox, about 220 meters southeast of the Lifepod. Drop out of the hatch, take the left exit from the cave, and two small sulfur pieces sit out in the open in front of you. It's not enough to fuel sustained crafting, but it's plenty to make your first batch of advanced components.
Before leaving the Lifepod, open the character menu and turn on all landmark signals. The blackbox and biome markers make navigation to these spots much faster.
The best sulfur farming spot
The richest deposit cluster sits on a tall pillar that rises almost to the surface, perched at the boundary of the lava region. Two ways to reach it:
| Route | Reference point | Direction and distance |
|---|---|---|
| Direct | Lifepod | 250 m south-southeast |
| Via blackbox | Chap's Blackbox | 90 m northeast |
You'll know you're in the right place when you see large Coral Crabs patrolling the area and a human-made platform near the base of the pillar. The pillar itself is studded with yellow crystal nodes.
What you can harvest from the pillar
Circle the pillar fully to clear every node. A complete sweep gives you roughly 24 sulfur from the pillar alone.
| Deposit type | Count | Tool needed |
|---|---|---|
| Large sulfur deposit | 4 | Sonic resonator |
| Medium sulfur deposit | 3 | Sonic resonator |
| Loose pieces | Several | Hand pickup |
Need more? Two nearby spots extend the haul:
- Small pieces on the rock formation to the southeast of the pillar.
- More small pieces scattered on the fiery coral structures to the northeast.
How to mine efficiently
Step 1: Approach the pillar from the cooler side and identify the four large nodes first. These give the highest yield per hit and are the priority targets.
Step 2: Equip the sonic resonator and break each large deposit, collecting the drops before moving on. Sulfur shards can scatter slightly, so grab them as you go rather than circling back.
Step 3: Sweep the medium deposits and loose surface pieces on a single rotation around the pillar. Then peel off to the southeast rock and northeast coral structures if your inventory still has room.
What to craft first
Once you're back at base, sulfur slots straight into the recipes that gate the next tier of equipment. Strong acid is the most common immediate use, since it feeds fiber mesh and, by extension, the rebreather and other essentials. Advanced wiring kits unlock further base modules and vehicle upgrades.
If you only have mild acid available in the fabricator so far, you'll need a processor in your base before you can refine the stronger compound. That, in turn, requires a different rare material to craft, but the sulfur you just mined will be waiting when it's ready.