Crystals are a type of block that were first added in
or their ore) in groups in caves, facing any direction. To collect their material, they need to be mined with an
or better (or bronze pickaxe or better for glowstone), with each crystal yielding one resource - Edhelvir and Gulduril crystals have a base chance of 40% to drop any. To collect the crystal block itself, they need to be mined with a silk-touch pickaxe.
They all have a light level of 12, which is 1 more than their ores but less than torches.