X-Ray

Once you reach Mining level 250, you gain the X-Ray Ability. Using this ability, you can see through normal stone, which allowes you to eventually spot ores. To activate the ability, you need to put a prismarine crystal in your offhand, sneak and look straight down. While the ability

is active, which lasts for 10s, you can't move or jump. After that, you need to wait at least 5min until you can use the ability again. One thing you should remember is that you can only see through the normal stone. So if you're surounded with granite and andesite you should not use X-Ray.