The Last Caretaker Quantum Crystal: Where to Find It and What It Is For

Quantum Crystal Ore is a green, glowing deposit, and most of it is around the Quarantine Stacks.

The four stacks stand close together on the in-game map: Amen at 146, -38; Chorus at 147, -32; Dawn at 150, -46 and Aurora at 160, -38.

Many of the crystals grow high on the stacks, where you cannot climb. Shoot them and they drop down to you; at night their green glow makes them easy to spot from the water.

Break the ore with the Dismantle Tool to get Quantum Crystal Nuggets, then put the nuggets in the Recycler: each one gives 1 Quantum Crystal. It is an Artifact-rarity material, so expect small amounts.

Quarantine Stack Amen holds more once its quest is done: boulders in the treasure room break apart with large O2 grenades, and a cave system behind unpowered doors has more ore.

Sending humans to space can pay out Quantum Crystal: it is sometimes among the gifts that come back after a delivery.

The rewards pod also brings Quantum Duplicators. Put one in the Recycler and it breaks down into the parts it was made from, including 1 Quantum Crystal.

Yes, sometimes. Feed the Recovery Grinder Plasma Gel or Neutronium and Quantum Crystal can come out, but not one for one, so put in more than you need.

Each of the three Spires has a few Quantum Crystals, enough between them for the Continuity Token. The Spire of Exodus, nearest the Quarantine Stacks, is at 183, -38.

Update 5.5 (August 31, 2026) put Quantum Crystal into the Reactive Core recipe, where Plasma Gel used to be.

A Reactive Core takes 3 Titanium, 1 Quantum Crystal and 6 Aluminium, plus 5 Wh to craft.

The sonar’s Deep Scan-500 Add-On (skill tier 23) needs a Reactive Core and an Advanced Alloy Mesh, so it costs you one crystal.

Update 6’s Continuity Token, the item that opens the Transfer Gate, takes 4 Quantum Crystals.

Plan on 4 for the Continuity Token, then 1 more for every Reactive Core you build.