Kermiculite

Kermiculite is the green mineral. Kermiculite is rare and there's only three ways to gain some:

1. When the game starts a few kermiculite asteroids are spawned with high velocities. You wont be able to mine much from them, but they are the earliest way to get some green.
2. After 8-11 min a field of kermiculite asteroids is spawned (with the same distance to both battlecruisers). You're notified before the spawn and it's position will be pinged on the minimap. When this field is empty another will spawn in 6-9 min.
3. You can use the Matter Replicator to create kermiculite from energy, but this is very expensive

Kermiculite is used for most advanced upgrades and is more valuable than pyromantite, veldite and chalcorium.