How to get the mace in Minecraft (heavy core and breeze rod)
Trial chambers are copper and tuff structures that start between Y -40 and Y -20 in the Overworld.

Tuff is a dark gray volcanic stone found in large patches deep underground, mostly around the deepslate layer. It is also the main building material of trial chambers, alongside copper.
It cannot be crafted; it can be found in chests. It is mined with a pickaxe.
Tuff mines as fast as ordinary stone and drops itself, without needing Silk Touch. Underground it often sits next to ores, and it shows up in big blobs that are easy to quarry.
On its own it looks rough, but it is the base of a full building set: Polished Tuff, Tuff Bricks, chiseled tuff and chiseled tuff bricks, each with slabs, stairs and walls. A Stonecutter turns it into any of them in one step, and four tuff also craft four polished tuff.
The tuff blocks you see in trial chambers are this same family, so exploring one is a good way to see how they combine with copper.
This item has no crafting recipe.
Trial chambers are copper and tuff structures that start between Y -40 and Y -20 in the Overworld.
Mining the block drops it. It can be found as loot in Trial Chambers.
It is a building stone and the base of polished tuff, tuff bricks and chiseled tuff. It is an ingredient in 13 recipes, made at the Stonecutter and Crafting Table; for example Polished Tuff Slab, Polished Tuff Stairs, Polished Tuff Wall, Tuff Brick Slab, Tuff Brick Stairs and 5 more.
The fastest tool is the pickaxe.
Placed under a Note Block, Tuff gives the Bass drum sound.