Dark Craggy Peaks

It would be really cool if there were like a black dark mountains biome with big crags something like the basalt deltas with black or grey stone and sharp cliffs so we can build dark edgy castles at the top of the already massive mountains. it should probably be as rare as a mooshroom island. also there could be a naturally spawning dungeon with lava pouring down. it would be really nice to have in the world and not have to spend hundreds of hours terraforming one to be like this. i know it is very similar to a basalt delta so maybe not crags but maybe smooth peaks but very high.