As expected from the name, this stratum is crystal themed. It would be a T3 mission. Before I get into detail on the levels, boss etc. There are a few things you need to know.

- This area contains semi-crystalised versions of enemies, which are different in 2 ways. Their damage types are changed, so that all attacks that woukd deal normal damage deal 1/4 piercing damage, ex. A retrode smack would be split normal-piercing, but all attacks that would deal special damage still deal that damage. Also, all crystal enemies will be only half as resistant/weak to the damage types they normaly would be. Now to the actual levels:

Floor One. Depth 25. Trail to the Mines:
The first half of this floor is a regular randomly generated clockwork tunnels floor, but with a few clear crystals growing out of the sides of the platforms. In some areas the crystals tear through the floor (purely for show). It is slightly different from regular clockworks tunnels in that it has no set monster type, so any family can spawn.

Once you reach 60%ish point, the platforms become rocky, with moss that slow you down like swarm seeds, and crystals growing out of the ground that cause status effects depending on their color. (excluding freeze to prevent getting stuck, and curse for obvious reasons). The floor continues on, the light level lowers, and enemies begin to be replaced by crystal versions. In the final room, their is a party button that activates a three wave battle:

Wave one:
3 crystal jelly cubes
2 regular lumbers
4 crystal gremlin demos (place down ionized salt bombs at a slower rate than other demos)

Wave two:
5 crystal zombies (breath attack fires out crystal bomb shards in an autogun pattern)
3 crystal howlitsers
2 Trojans

Wave three:
6 crystal devilites
6 Crystal wolvers
2 crystal alpha wolvers
1 trojan.

The elevator after the room is located next to a sign that reads "Crystal Energy Mines".

Floor 2. Depth 26. Caverns of Chaos:
You start of at a mining area with knights mining away at crystals, and are by the chief. He tells you about a mysterious new mineral discovered causing his men to go mad, and you have to go destroy it. There are heart boxes and a few treasure boxes next to him. You walk through a force feild, and are attacks by 4 crystrodes. After making your way down a mineshaft a cutscene triggers of the mineshaft enterance caving in. You receive a message from the mining chief saying there is another exit through the mines past the crystal, and wishes you good luck.

You enter a room with a party button that triggers three waves of crystal enemies. The waves are randomly generated, so they contain different enemies each time. The first and second waves contain 2 "Heavy" enemies, 4 "medium" enemies, and 4 "light" enemies. The third wave has 50% more of each. The room has a few shock crystal traps scattered around the floor. The elevator at the end of the floor is being taken over by crystals, which shatter when you descend.

Floor 3. Depth 27. The Mines:
This floor starts out with a short "maze" of fire crystals, which you must navigate carefully to avoid death. To add to the difficulty, respawning crystal howlitzers are located throughout it. Watch your step! There is a small 2 wave beast based battle afterwards, followed by a cavern filled with crystal energy on the walls. (No, you can take them). Gremlin miners can be found here, they are similar the thwakers, but attack with a pickaxe and can throw poison crystals at you. There are caved in areas in the walls, which if you approach them, a Trojan rams through.

A battle room is located after, it has 4 respwning crystal polyps. The first wave contains 20 crystals Zombies, and 8 crystal devilites. The second wave is the same but with 2 trojans. Before the third wave, stun crystals grow out the sides of the cavern walls, making the room about 70% its original size. 2 of the polyp spawners are destroyed, 2 Crystalline Deadnaughts spawn, along with 2 alpha crystal wolvers, and 8 crystal retrodes. The deadnaughts can cause shock, and rarely, curse.There is one more area before the final room, which involves minecarts flying across tracks, which require quick reflexes to get past. Mercurial armour will help here.

The final room is about the size as the last FSC room, with a checkerboard pattern of spike traps similar to the left room of garden of goo. The first wave is ten crystal lichens (Like poison ones but no status), and 10 Jelly cubes, as well as 3 respawning crystal polyps. The second wave contains 10 crystal zombies and greavers, and one Trojan. The polyps are replaced with howlitzers. The third wave is 4 alpha crystal wolvers, 15 regular crystal wolvers. The final wave contains one deadnaught and one trojan, as well as 10 crystal gremlin thwakers, and 10 crystal devilites.

Final floor. Depth 28. Shards of Terror:
This is the boss floor. There is nothing before the boss other than heart pads, so I'll get right to it.

Boss: Void Crystal:
Description: 3 crystals in a triangle pattern, black at the bottom fading to red at the tip. Pink electricity joins towards the middle and forms the swarm eye. Smaller crystals orbit around it.

Note: this boss is COMPLETELY unable to move.

Stage one: The crystal has 3 attacks, all deal pure normal damage.
1. It throws out ionized salt bombs at random areas around him, can cause shock.
2. Jabs spikes through the ground similar to jelly cubes, but has a larger area of affect
3. Eye lowers to the ground and shoots out crystals in an autogun charge pattern, takes a few seconds to charge, in which time he aims for you. He is only vulnerable while aiming.
Attacks 1 and 2 can be performed at the same time.

Stage 2:
The eye lowers again, with a force field around him, generated by two crystals on the sides of the cavern. 4 Greavers spawn and respawn 5 seconds after being killed. He constantly repeats attack 3 over and over again, but is not vulnerable until the crystals powering his shield are destroyed. This must be repeated twice. After this stage, the 3 crystals start to crack

Final stage:
The screen starts to shake, and rocks fall from the cavern in random areas, marked by shadows. His shield is up again, and is powered by 3 crystals now. He can do all the attacks of stage one, as well as shoot out crystals that reflect off walls, only 2 can be active at a time, and disappear after 45 seconds. Destroy the crystals, attack him when the eye comes down, repeat twice.

Once you kill him, you receive a message from the mining chief congratulating you, and you head back to the elevator and return to Haven.

Rewards: Void Shards (Token)
20 Tokens: Ionized Salt Bomb/Radiant Sun Shards
10 Tokens: Crystal Shield 3*- Gives peircing, normal, shock, and stun resistance. Upgrades to 5*.
15 Tokens: Shard Blaster 3*- 3 shot piercing gun, speed identical to Valiance. Upgrades to 5*.