Encroaching Mycosynth is a rare Artifact card from Phyrexia: All Will Be One Promos (PONE), collector number 47p. Current market price: $0.80 (foil $1.12), TCGplayer market prices via Scryfall.
Nonland permanents you control are artifacts in addition to their other types. The same is true for permanent spells you control and nonland permanent cards you own that aren't on the battlefield.