You can now use molotovs or other non-player forms of damage to destroy the lifecrystals in the deep caves. They have 600 health, and will drop a "lifecrystal shard" which you craft with a pickaxe in order to receive a lifecrystal.
UPDATE 1.1.0: Some experimental changes to cave segments, increasing the spawnrate of resources as well as letting them potentially spawn higher. Also makes caves a little bit more winding by changing the spawnrate of certain cave segments. Now Fully Tested™.