Jakub Wysocki writes:
Hi! I made 100% procedural Obsidian/Crystal material in Blender 2.8.
The material is not using any UV's so it's easy to apply to any object. Nodegroup settings makes it easy to adjust the final appearance. Also it is using micropolygon displacement in Cycles, so to be able to use it in Eevee (or game assets), you have to bake the textures first.
If you interested in testing it out or checking node setup you can find more previews and free download link on my Artstation.