Subnautica 2: How to Get Celestine

TL;DR

Celestine is a mid-to-late game mineral found exclusively in the alien biome, roughly 1,200 to 1,400 meters east of the Lifepod.
It appears as bright blue crystalline clusters on rock walls, cliff faces, and the seabed — don’t confuse it with Calcite, which looks similar.
You need the Tadpole and the Sonic Resonator to farm it efficiently. Large nodes can only be broken with the Sonic Resonator.
The best farming spots are southeast of the Alien Ruins, around the Alien Observatory, and in the Metal Farm area.
Scanning your first Celestine node unlocks the Strontium Processor recipe automatically.
Key crafting uses: Tadpole Depth Module Mk. I, Modification Station, and Strontium ingots.

Celestine is the resource that opens the door to the deep ocean in Subnautica 2. You need it to craft the Tadpole Depth Module, which raises your submarine’s safe diving limit from 250 meters to 450 meters. Without it, a huge portion of the map stays out of reach. The problem is that Celestine doesn’t spawn anywhere near the Lifepod — it lives in the alien biome far to the east, past a Leviathan, at depths that require proper preparation to reach.

This guide covers where to find it, how to mine it, and exactly what you need it for.

Table of Contents

What Is Celestine in Subnautica 2?

Celestine is a blue crystalline mineral found in the deep alien biome. The in-game PDA describes it as strontium sulfate (SrSO4) — the skeletal remains of microorganism colonies that synthesized the compound as ballast. Harvesting it gives you raw Celestine, which can be used directly in some crafting recipes or processed at the Processor into Strontium for advanced upgrades.

It’s not a common ore like Titanium or Quartz. You won’t find it near the starting area or during casual early exploration. Celestine is a progression gate — the game is effectively telling you to push east, build the Tadpole, and prepare for deeper water before you can access it.

What You Need Before Farming Celestine

Don’t head east unprepared. Here’s what you need before making the trip:

Tadpole submarine — The alien biome is roughly 1,200 to 1,400 meters east of the Lifepod. Swimming is dangerous and slow. The Tadpole crosses this distance far more safely, protects you from the Collector Leviathan, and gives you unlimited oxygen while piloting. See our full guide on how to build a Tadpole in Subnautica 2.
Sonic Resonator — Celestine only spawns as large nodes that must be broken with the Sonic Resonator. You cannot harvest it by hand or with standard tools. Medium nodes can be hit with your Scanner for 2 pieces, but large deposits require the Resonator. You cannot farm efficiently without it.
Rebreather — The best Celestine deposits are at 250 meters or deeper. The Rebreather removes the depth-based oxygen drain penalty, giving you a flat 1 unit per second loss at any depth. Don’t leave without it. See our guide on how to increase oxygen in Subnautica 2.
Heat Tolerance adaptation — Parts of the alien biome and surrounding areas involve thermal zones. Having the adaptation active before you go keeps you safe from environmental heat damage. See our guide on how to get the Heat Tolerance trait.
Tadpole fully repaired — The Collector Leviathan patrols the trench between the hot biome and the alien biome. It can and will grab your Tadpole. Go in with full hull durability so a single hit doesn’t cripple you. Keep your Repair Tool ready.
Air Bladders and spare Power Cell — You’ll be parking the Tadpole near 250 meters and swimming out to mine nodes. Air Bladders are your emergency exit. A spare Power Cell ensures you can make the long trip home.
Completed the Tadpole Pens — Celestine farming comes after the Tadpole Pens quest, not before. If you haven’t opened the locked door yet, read our guide on how to get the Tadpole Pens keycode first.

What Does Celestine Look Like?

Celestine grows as jagged clusters of bright, saturated blue crystals embedded into rock surfaces, cliff walls, and the seabed. In the darker water of the alien biome, the blue glow makes them fairly visible from a distance. The nodes are usually found on elevated rocky ledges, along cliff faces, and scattered across the seafloor near alien structures.

Important: Calcite looks very similar — both are blue crystal formations. They are completely different resources. Always check the on-screen label before harvesting. Celestine shows the item description “Local source of radioactive Strontium. Burns brilliant red.” when you collect it. If your harvest doesn’t register in the Celestine slot, you hit Calcite. Recheck the node name and move on.

Scanning a Celestine node for the first time also triggers a “NEW BLUEPRINT SYNTHESIZED” notification and unlocks the Strontium recipe in your Processor. If that notification doesn’t appear when you harvest your first blue crystal, you’re mining Calcite, not Celestine.

Where to Find Celestine in Subnautica 2

All confirmed Celestine deposits are in the alien biome, roughly 1,200 to 1,400 meters east of the Lifepod. You won’t find any closer to the starting area. Here are the three main farming zones.

Where to Find Celestine subnautica 2 alien ruins waypoint

Location 1 — Southeast of the Alien Ruins (Best Early Spot)

This is the most accessible Celestine farming location for players who have just completed the Tadpole Pens. Head to the Alien Ruins research base waypoint, then travel roughly 200 to 290 meters southeast, over the cliff edge, and down to the rocks below at a depth of around 250 meters.

There is a significant concentration of Celestine nodes along the cliff walls and rocky terrain in this area. Two Needlers also patrol the Needler nest nearby — the closer you get to the nest, the more dangerous it becomes. Start on the outer edges of the zone, harvest what you need, and avoid going too deep into the nest territory until you’re better equipped.

This is the ideal first Celestine run because you can park the Tadpole just above the 250-meter crush depth limit and swim short distances to the nodes on the rocks below. You stay close to your oxygen source while still hitting good deposit clusters.

Location 2 — Alien Observatory

The Alien Observatory is another reliable Celestine zone, roughly 940 meters east of the Lifepod’s general direction once you’re in the alien biome. Head toward the Observatory waypoint and check the rock faces to the south and along the cliff walls at depth.

This area has fewer hostile threats than the Needler nest near the Alien Ruins, making it a better option if you want a calmer farming run. The darker water here also makes the blue glow of Celestine nodes easier to spot at a distance, so visibility works in your favor. Node density is somewhat lower than the southeast Alien Ruins spot, but it’s a much safer farming loop.

Location 3 — Metal Farm Biome

The Metal Farm area sits roughly 700 meters east-southeast of the Alien Base, making it one of the further Celestine locations but also one of the most resource-rich areas in general. Celestine nodes appear across the biome alongside other high-tier materials like Troilite.

Be aware that this area is close to the current edge of the map and has a Leviathan roaming nearby. Come here with a fully repaired Tadpole and don’t linger in open water. If you use the Scanner Station to track nearby materials, the Metal Farm shows up as a dense resource zone worth the trip once you have the Depth Module equipped and your Tadpole upgraded.

How to Mine Celestine

Celestine only spawns as large node clusters. Here’s the mining process:

Park the Tadpole at or above 250 meters depth — don’t push it deeper without the Depth Module or the hull will take damage.
Exit the Tadpole and swim to the nearby Celestine node on foot. Keep an eye on your oxygen meter the whole time.
Equip the Sonic Resonator and use a Charged Blast on the node to break it apart. Each large node yields 1 to 5 pieces of Celestine depending on size.
Collect the pieces and swim back to the Tadpole to refill oxygen. Repeat.
When your inventory and Portable Locker are full, return to base.

The key habit here is treating the Tadpole as a parked oxygen station rather than trying to go deeper in it. Exit, mine quickly, re-enter for air, exit again. Short loops keep you alive at these depths. Don’t try to push the Tadpole past its crush limit for one extra node — the repair cost isn’t worth it and you risk losing the vehicle entirely.

Attach a Portable Locker to the Tadpole’s rear hardpoint before the trip so you can carry more Celestine per run. See our guide on how to increase inventory space in Subnautica 2 for more ways to maximize what you bring home.

How to Process Celestine into Strontium

Once you scan your first Celestine node, the Strontium recipe unlocks automatically in your Processor. To make Strontium, place 2x Celestine into the Processor. After roughly 30 seconds of processing time, it outputs 1x Strontium.

Strontium is a mid-to-late game ingredient used in several advanced upgrade recipes. Because the conversion ratio is 2:1, it’s worth farming more Celestine than you think you need for an immediate recipe. Running out of Celestine blocks the next upgrade and forces another long trip east.

A good rule: gather enough Celestine for your immediate craft and then a handful extra for processing. That buffer lets you keep progressing without additional farming runs back to the alien biome every time a new recipe comes up. Read our guide on how to build a Processor and craft ingots if you haven’t set one up yet.

What Is Celestine Used For in Subnautica 2?

Celestine is a fairly focused crafting material. It doesn’t appear in many recipes, but the ones it does appear in are all important. Here’s the full list:

Tadpole Depth Module Mk. I

This is the primary reason most players farm Celestine. The Depth Module raises the Tadpole’s maximum safe diving depth from 250 meters to 450 meters, opening up a massive portion of the map that is otherwise inaccessible. It’s crafted at the Modification Station.

Recipe: 3x Celestine, 2x Enameled Glass, 1x System Chip.

Enameled Glass is made from Creature Enamel and Glass at the Fabricator. For Quartz to make Glass, see our guide on how to get Quartz in Subnautica 2.

Modification Station

The Modification Station is the base structure where all Tadpole upgrade modules are crafted. You need it to make the Depth Module itself, so build this first.

Recipe: 2x Titanium, 2x Celestine, 2x Copper.

For Titanium and Copper, see our guides on how to get Titanium and where to find Copper.

Strontium (Processed)

Processed from 2x Celestine at the Processor. Strontium feeds into several advanced upgrade recipes including the Cavitation Muffler and Strike Armor Tadpole upgrade. Farm extra Celestine so you always have Strontium available for upcoming recipes.

Decorative Base Items

Celestine is also used in a handful of decorative Habitat Builder items: the Axum Pot, Axum Street Lamp, and Axum Wall Lamp. These are aesthetic additions to your base and are low priority compared to the upgrade recipes above. Save your Celestine for the Modification Station and Depth Module first. Come back for decorations once you have a surplus.

Tips for Efficient Celestine Farming

Set up a small outpost near the Alien Ruins. A single corridor with a Biobed and a Tadpole Dock nearby means you can respawn close to the farming zone if something goes wrong, and recharge your submarine between runs. Read our guide on what to build in your base first to plan the outpost efficiently.
Get the Depth Module before pushing deeper. The first Celestine run is specifically to farm enough for the Depth Module. Once it’s crafted and equipped, return to the same farming zone — you can now take the Tadpole much deeper, reaching more nodes and operating more comfortably.
Farm alongside other alien biome materials. Creature Enamel, Conduit Crystal, and other alien biome resources share the same zone. Run a combined gathering trip rather than making separate visits.
Don’t force the Tadpole deeper than 250m without the module. One extra ore node is not worth hull damage and a potential vehicle loss mid-dive. The deposits near the 250-meter mark are sufficient for your first run.
Watch for the Collector Leviathan crossing the trench. It patrols the gap between the hot biome and the alien biome. If you see it, wait for it to pass before crossing. Don’t engage it unless you have to. If you die in transit and lose your inventory, see our guide on what happens when you die in Subnautica 2 to recover your gear.
Use the Scanner Station to confirm Celestine density before the trip. Building one in the alien biome gives you a resource map showing exactly where the highest concentrations are. It saves time on every subsequent run. Learn how to set one up in our guide on how to build a Scanner Station.

Celestine Farming Priority Order

Complete the Tadpole Pens and unlock the Alien Ruins waypoint. See our guide on how to get the Tadpole Pens keycode and open the locked door if you haven’t done this yet.
Build the Tadpole and equip the Rebreather before heading east.
Cross the Collector Leviathan trench in the Tadpole and reach the alien biome.
Head southeast of the Alien Ruins, dive to 250m, park the Tadpole, and mine Celestine nodes with the Sonic Resonator.
Scan your first node to unlock Strontium in the Processor.
Return to base and craft the Modification Station first using 2x Titanium, 2x Celestine, and 2x Copper.
Craft the Tadpole Depth Module Mk. I at the Modification Station using 3x Celestine, 2x Enameled Glass, and 1x System Chip.
Equip the Depth Module and return to the alien biome — you can now dive 200 meters deeper on every subsequent run.

More Subnautica 2 Guides

Subnautica 2 is available now in Early Access on Steam and Xbox, including Xbox Game Pass.