What is "quarry tile"

n. A very hard ceramic tile used e.g. as flooring, usually 1/2 to 3/4 inches (13 to 19 mm) in thickness, made by the extrusion process from natural clays or shales.

Quarry tile is a building construction material, usually to inch (13 to 19 mm) thick, made by the extrusion process from natural clay or shales. Quarry tile is manufactured from clay in a manner similar to bricks. It is shaped from clay, and fired at a high temperature, ~2,000 F°.