In this guide, you will learn how to find Kyanite in Subnautica. You have to follow all the steps carefully to find it.
The first thing you will need to do is head northwest or 1-2 bumps to the right of the northwest, starting from the coral tube sticking up out of the water. Keep moving until you reach the blood kelp trench next to the northwestern mushroom forest biome.
It is recommended to have a prawn suit with an Mk1 depth module, a drill arm, a high capacity O2 tank, a sea glide, a cyclops with an Mk2 depth module. You will need extra power cells for your cyclops if you don’t have the thermal reactor module, a reinforced dive suit, and a survival knife.
The main threat you will encounter in the lava zone is the sea dragon leviathan; you have to avoid them as best as you can. And the lava lizard, which you can kill using the stasis rifle and normal survival knife. You will also face the warper; you can attack them using your knife until it warps away, or you can run away.
The coords for the location are (-87.3, -1172.0, -94.0).
There is also lava larva in the inactive lave zone which will latch onto your vehicle/cyclops and drain its energy. If they do, then you can cut them off using the knife.
Once you are in the lost river, you have to look for a large drop to about 800m.
It is the drop that you are looking for.
Once you are down the drop and in an area that looks like this, you will need to make your way to the path/entrance on the right. And you will end up in the tree cove part of the lost river.
After that, you have to go around the large tree and continue straight through the tree cove until you reach an area where you can descend into a large crevasse/cavern.
Once you reach a large cavernous area that looks like this, you have to head to the right and continue through the path. You will eventually reach a large open area in the inactive lava zone.
The next thing you have to do is search primarily on the walls and seafloor for kyanite deposits.
If you keep heading straight or towards the center of the large open area, you will come across the lava castle. Outside the lava castle, you can find both kyanite deposits and kyanite that you can pick up without a prawn suit.
Here is the lava castle.