Geology Enthusiast is a rare Creature — Human Artificer card from The Brothers' War (BRO), collector number 289. Current market price: $0.31 (foil $0.50), TCGplayer market prices via Scryfall.
At the beginning of your end step, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.") {6}: Draw a card and put a +1/+1 counter on this creature.