I'd really like to get rid of LockeZ. His play style is way too unpredictable. He's always like this too. If he ran a country, he'd just kill and imprison people at random until crime stopped.
The Cobolt Cave systems is full of...well...Cobolt. But there are also seams of Labrynne Midnight, a blue gemstone with weird properties. It gets used in some puzzles down there.