Clinker bricks were originally discarded because they were discolored or distorted. In the early brick firing kilns, the wet bricks too close to the fire changed into the volcanic textures and darker/purplish colors of clinker bricks.

Modern brickmaking techniques produce a more consistent, if boring, product.

The name “Clinker brick” is said to come from the sound made by banging the brick together as they are heavier than regular bricks. The term is also used for the hardened residue of coal fires that have a similar texture.