Defeat at least one Mechanical Boss
Find Chlorophyte Ore in the Underground Jungle
Use a Pickaxe Axe, Drax, or better
Mine the ore directly from the Jungle
Bring a strong pickaxe or drill for faster mining
Smelt Chlorophyte Ore into Chlorophyte Bars at a Furnace
Use Chlorophyte Bars to craft Chlorophyte tools and armor