What is Slate?Slate is a hard, dense, and fine-grained low-grade metamorphic rock that splits into thin slabs along planar surfaces. This splitting, known as slaty cleavage, results from recrystallization under pressure and commonly develops at an angle to the bedding planes. Slates are formed from clays, shales, volcanic ash, and other fine-grained rocks. Minerals present are quartz, sericite, chlorite, some graphite, titanium oxide, and iron oxides.
What is Limestone?: A fine-grained, sedimentary rock. Limestone is composed primarily of calcium carbonate in the form of calcite or aragonite. Trace amounts of dolomite, iron oxide, quartz, clay, or organic particles can also be present. Due to these impurities, limestone can vary in color from a cream to yellow to pink to brown to celadon, mustard, and dark gray. Limestone is formed from compressed and cemented seashells and marine animal skeletons (reefs) or reprecipitation (stalactites, stalagmites). It is softer and more easily worked than marble.
What is Sandstone?: Sandstone is a sedimentary rock made of sand-sized grains of minerals, mostly quartz and feldspar, or older rocks held together by one of several types of cement or a fine, muddy matrix. Sandstones vary greatly in color, composition, texture of grains, degree of cementation and layering. Ripple marks, planks, and animal trails may appear on bedding surfaces, which have been retained when we cut the stones.
How easy is it to install? Stones are installed like other tiles. Use a wet saw and grinder to cut, mortar and grout to install. Stones must be sealed after installation to resist staining.
How do you seal stone? You can purchase stone sealant from a variety of sources (local hardware stores, tile supply stores, on-line Eco-Friendly building supply stores). Follow the manufacturer's instructions. This typically involves spraying the stones until they are saturated with sealant in a well-ventilated area. Some sealants will last up to 60 years with a single application.
Why use stone over ceramic tile? Stones are typically more slip-resistant than a glazed ceramic tile. Stones also have a more natural and timeless design, so they would be less likely to be replaced. Stones are also repairable. (for example, a chipped limestone or slate tile may be touched up with sandpaper and sealant)
Is stone easy to clean? It depends on the stone. If the stone is already sealed, mopping is usually sufficient for deep cleaning. The more clefted (jagged) the face of the stone, the more likely it will be to catch debris from shoes etc. That said, stones are great at hiding dirt, so if you want something for a mudroom, commercial space, or busy hallway, a little extra sand on the floor will not harm a stone floor, and it will not be screaming for a cleaning after a little traffic. Limestone tiles are smoother than slate, but are typically lighter in color. A dense, lightly clefted slate such as Zephyr is a great option for extremely high traffic areas that must be easy to clean.
Can stone tiles be used for countertops and backsplashes? Yes. Appropriate backer boards (Durock, Hardibacker etc) should be used and the same installation methods apply. Tiles can be set tighter than on the floor for minimal grout joints. It is imperative to seal the area completely after grouting to make cleaning easier. Stone tiles are a much less expensive, but equally beautiful option for countertops than their solid-slab counterparts. ($5/sq.ft. vs. $60/sq ft)