The Oxidized Copper Chest is the final oxidation stage of the Copper Chest, featuring a fully aged teal surface with prominent green tones. It functions the same as other copper chest variants, serving as a 27-slot storage block that can merge with another to form a Large Copper Chest with 54 slots. Players can prevent oxidation by applying Honeycomb to create a Waxed Oxidized Copper Chest or use an Axe to scrape it back to an earlier stage.

The Oxidized Copper Chest naturally forms when a Weathered Copper Chest continues to oxidize over time or when a Copper Golem is created using an Oxidized Copper Block. Its oxidation changes only the visual appearance, not its functionality. The Oxidized Copper Chest can be opened unless obstructed by a conductive block, renamed with an Anvil, or locked using commands. Copper Golems can interact with it by taking items from the chest and depositing them into nearby Wooden Chests, supporting simple automation setups. The Oxidized Copper Chest must be mined with a stone pickaxe or better to drop itself.