Waxed Block of Copper is a non-oxidizing variant of the block of copper, created by applying honeycomb to prevent oxidation. Unlike standard copper blocks, waxed variants do not change color over time.
Waxed blocks of copper generate naturally in trial chambers and can also be crafted from a block of copper and a honeycomb. They can be stonecut into slabs and stairs, or crafted back into nine copper ingots. Mining requires a stone pickaxe or better, and scraping with an axe removes the wax, allowing oxidation to resume.