Celestine is one of the most important mid-to-late game resources in Subnautica 2. It is the raw mineral you process into Strontium, which is required to repair the Alien Power Plant — a critical story objective — and to craft essential upgrades for your Tadpole submarine. If you are pushing into the Alien Ruins biome and wondering what those blue-glowing crystal clusters are, this guide covers everything: what Celestine is, exactly where to find it, how to harvest and process it, and every confirmed recipe that uses it.
What Is Celestine in Subnautica 2?
Celestine is a harvestable mineral deposit found in the deeper biomes of Planet Zezura. It is named after the real-world mineral celestine (strontium sulfate, SrSO₄), which is the primary ore source of strontium on Earth. Subnautica 2 faithfully mirrors this chemistry: you mine Celestine deposits, then process the raw mineral into Strontium using the Processor.
Key facts at a glance:
| Property | Detail |
|---|---|
| Resource type | Mineral deposit (harvestable) |
| Processed into | Strontium |
| Processing machine | Processor |
| Processing time | 30 seconds |
| Harvesting tool | Sonic Resonator |
| Required for | Alien Power Plant repair, Tadpole upgrades |
Visually, Celestine deposits are crystalline, shard-like clusters that protrude from walls and the ground. During the day they appear silver; at night they glow blue, which actually makes them easier to spot during a night dive.
Where to Find Celestine — Alien Ruins Biome
All Celestine deposits are located in the Alien Ruins biome, east of your Lifepod. Multiple explorers have confirmed this location, and it is tracked on the MapGenie interactive map for Subnautica 2.
How to Get There
Head east from your Lifepod. The journey takes you through several distinct zones, so navigation matters:
- Surface crossing. Stay near the surface as you swim east. You will pass over shallow terrain before reaching a drop-off zone that descends into deeper water.
- Heated zone. The route passes through a geothermally heated area that deals constant damage. Heat Tolerance adaptation is strongly recommended before making this trip. If you have not acquired it yet, stay near the surface to minimize damage while crossing.
- The Tower. Look for a tall structure visible above the waterline. This surface landmark confirms you are in the right area.
- Descent. Dive down past the purple roots and angel comb formations. The Celestine deposits begin appearing on walls and near the ocean floor around 250 meters depth.
Key Landmarks Near Celestine Deposits
- The Tower — visible from the surface, your primary navigation beacon
- Research Outpost — a nearby building you can use as a shelter
- "Rosetta Stone" — a named landmark in the immediate area
- Alien Power Plant — Celestine deposits are clustered very close to the Power Plant itself
- Purple roots — found above the angel comb area, marks your descent point
Best Farming Spot
The densest concentration of Celestine is on an underwater mountain near the Alien Ruins, at approximately bearing 165 degrees from the Lifepod. This single location contains roughly 15 deposits — enough to fill your inventory in one trip. If you need Strontium in bulk for the Power Plant repair, this is the place to go.
Environmental Hazards
The Alien Ruins biome is dangerous. Be prepared for:
- Leviathan patrol. A leviathan actively hunts in this area. When the ambient audio suddenly goes quiet followed by a squealing sound, a leviathan is nearby. Surface immediately or take cover inside structures.
- Depth and oxygen. Deposits sit around 250 meters deep. Bring extra oxygen tanks or use your Tadpole vehicle. Running out of air this far from the surface is lethal.
- Heat zone en route. The crossing deals constant thermal damage without Heat Tolerance.
How to Harvest Celestine
You need the Sonic Resonator to break Celestine deposits. Standard tools will not work. Aim the Sonic Resonator at a deposit and fire to shatter it into collectible pieces.
Tips for efficient harvesting:
- Farm at night. Celestine deposits glow blue in the dark, making them significantly easier to spot against the deep ocean environment.
- Bring the Tadpole. A submarine gives you oxygen security, inventory space, and speed — all critical for a deep, hostile farming run.
- Fill your inventory in one trip. Deposits are plentiful in the Alien Ruins area. Do not make multiple trips when one well-planned run will do.
- Process immediately. Celestine converts to Strontium in just 30 seconds. Set up a Processor at a nearby base or process it as soon as you return.
Processing Celestine into Strontium
Place raw Celestine in the Processor. After 30 seconds, you receive Strontium. This is the form used in all crafting recipes.
There is no reason to hold onto raw Celestine. Process every piece as soon as possible.
Crafting Recipes That Use Strontium (Celestine)
Alien Power Plant Repair — Confirmed Recipe
Repairing the Alien Power Plant is a major story objective and the single biggest sink for Strontium. The exact recipe is:
| Ingredient | Quantity |
|---|---|
| Titanium Ingot | 10 |
| Strontium | 10 |
| Mangalloy Ingot | 10 |
That means you need 10 Strontium, which translates to 10 Celestine deposits processed through the Processor. Given the quantities of Titanium Ingot and Mangalloy Ingot also required, plan this as a dedicated farming objective rather than something you accumulate passively.
Tadpole Vehicle Upgrades
Strontium is also used at the Modification Station to craft upgrades for the Tadpole submarine. Confirmed upgrade modules include:
- Engine Efficiency Module — improves fuel economy for longer expeditions
- Depth Module Mk 1 — extends the Tadpole's operational depth range
These upgrades make your submarine more capable and are especially useful if you plan to explore deeper biomes beyond the Alien Ruins.
Preparation Checklist Before Farming Celestine
Before you set out for the Alien Ruins, make sure you have:
- Sonic Resonator — required to harvest deposits
- Heat Tolerance adaptation — acquired from an Angel Comb; essential for the heated zone crossing
- Standard Air Tank or better — deposits are around 250m deep
- Water Bottles and cooked food — the round trip is long
- Spare Basic Batteries — for your tools and vehicle
- Tadpole submarine (recommended) — for oxygen, storage, and Leviathan evasion
- Flares (optional) — useful for distracting predators in the area
Frequently Asked Questions
What does Celestine look like in Subnautica 2?
Celestine appears as crystalline, shard-like clusters growing on walls and the ocean floor. During the day they look silver. At night they glow blue, which makes them much easier to find.
Can you harvest Celestine without the Sonic Resonator?
No. The Sonic Resonator is the only tool that can break Celestine deposits. You cannot harvest them with the Survival Multitool or any other tool.
How much Celestine do you need for the Alien Power Plant?
You need 10 Strontium (processed from 10 Celestine), plus 10 Titanium Ingots and 10 Mangalloy Ingots. Plan to farm at least 10 Celestine deposits in one or two trips to the Alien Ruins.
Is there Celestine near the starting area?
No. Celestine is only found in the Alien Ruins biome east of the Lifepod, at significant depth. It is a mid-to-late game resource that requires preparation and suitable equipment to reach.
Is Celestine the same as Celestite from the original Subnautica?
They are based on the same real-world mineral (strontium sulfate). The original Subnautica uses the spelling "Celestite," while Subnautica 2 uses "Celestine." The gameplay role is similar — both are mineral resources — but Subnautica 2 adds the processing step (Celestine to Strontium) and ties it to the Alien Power Plant repair quest.
How do I survive the Leviathan in the Alien Ruins?
Listen for audio cues: when ambient sound drops to sudden silence followed by squealing, a leviathan is approaching. Surface immediately or take cover inside structures. Building a small base in the Alien Ruins area gives you a safe retreat point. Bringing the Tadpole submarine also helps — it is faster than swimming and can absorb a hit if you cannot evade in time.
Sources: In-game observation and cross-referenced video guides from multiple Subnautica 2 content creators. All recipe quantities confirmed via direct gameplay footage. Note that Subnautica 2 is in Early Access and details may change with future updates.
Looking for more Subnautica 2 guides? Check out our beginner's guide for your first hours on Planet Zezura, or the Early Access overview for everything you need to know about the current build.