Flagstone stairs are stair-like structures made of flagstone, a flat, layered sedimentary rock with earthy tones and irregular patterns. Common flagstone types include sandstone, slate, and limestone; each has a unique color and texture. These stairs can be installed in a variety of ways, including dry-laying over gravel or mortaring in place, depending on the desired appearance and ... https://texasgardenmaterials.com/product-category/landscape-materials/flagstone-pavers/