Which is better, white crystal or obsidian?

Same. White crystal is as powerful as obsidian. Obsidian is as strong as crystal, because obsidian itself is the most attractive gem among all spar, so in ancient China and even the west, obsidian has been used as an exorcism tool, even a treasure. Obsidian is a kind of natural glass, which is formed after the rapid cooling of volcanic lava, so it is difficult to crystallize. It belongs to impure crystal gems, including conchoidal fracture.