# Geologically, yes.

Clay is just a suspension of sand (tiny rocks and minerals), water, and humus (organic material) within extremely fine-grained igneous rocks. Technically, clay is a stone material even before you do anything with it.

Over time, heat and pressure squeezes out the water, and the humus breaks down and bonds with other materials (not unlike what happens in steel-making). This is how clay becomes sedimentary stone. Shale is a good example of this.

Firing a brick within an oven or kiln just accelerates the process.

# Practically, yes.

If it looks like a stone, feels like a stone, and clocks a Burning Fist guard in the head like a stone, then it might as well be a stone. Don't waste time at the table pondering this sort of thing.

# Rock vs Stone

Same thing, seriously, I know my players were RPing dwarves but they're the same thing. Usually rock refers to the object and stone refers to the material, but they're interchangeable, can we please enter the dungeon, please?