Mining the crystals is indeed a challenge, especially in the later stages of the game, where the Voids relentlessly mow you down with their lasers in a few shots, unlike where they hardly do any damage the first time you are supposed to go mine the crystals for Khador. Especially after level 20, one barely gets a few tons before losing both their armour and shield, so here are a few good tactics for you when mining Void Crystals if it gets too unbearable.