Minecraft wiki entry for Configured_feature, associated text: ore
 size: Value between 0 and 64. Does not directly correspond with the amount of blocks placed.[more information needed]
 discard_chance_on_air_exposure: Value between 0 and 1. The chance for an ore block to be discarded when it is exposed to air. Setting this to 1 makes the ore completely hidden.
 targets: A list of targets.
A target
 target: Rule test. The blocks to replace.
Template:Nbt inherit/rule test
 state: The block to use.
Block state[show]