flagstone

Flagstone (flag) is a generic flat stone, cutting regular rectangular or square in shape and usually used for paving slabs or walkways, patios, flooring, fences and roofing. It may be used for memorials, headstones, facades and other construction. The name derives from Middle English flagge meaning turf, perhaps from Old Norse flaga meaning slab or chip https://en.wikipedia.org/wiki/Flagstone