![Incorrect planet type (metal hole) Incorrect planet type (metal hole)](https://preview.ibb.co/khZLRd/incorrect.png)
It should be sandy planets. This is either an incorrect word or an incorrect coding since refinery needs gas planet and mineral needs "wet"=moist planet. Wet doesn't matter but dry is another planet type so needs clarified.
Edit: I compared a sandy and a moist planet and the sandy did indeed get the 20% bonus to metal production so this is merely an incorrect word