Flagstone is a flat sedimentary stone with fissile bedding planes. It is naturally split or cut into layers according to these planes and used for a variety of purposes like patios, fences, roofing, facades, memorials, and walkways. Flagstone is bound together by minerals like calcite, silica, and iron oxide. These internal materials are the cause of flagstone’s beautiful colors, one of which is a stunning blue.
The word flagstone stems from the Middle English word “flagge” which means turf. In the thirteenth century, Europeans began using flagstone for floors, walls, and ceilings. It was especially popular for the interior rooms of castles. Flagstone floors still exist in Scotland’s Muchalls Castle and England’s Lindisfarne Castle. Today, Chicago’s Portage Park is famous for its expansive flagstone decorations.