What are bricks made out of?

Brick is made from clay and shale - some of the most abundant materials on earth - and then fired in a kiln at up to 2,000° F. By going through a chemical-transforming, vitrification process in the kiln, the minerals in the clay/shale unit fuse together and become a material that looks great, lasts an incredibly long time.

I think bricks are made out of concrete