Stone Tile Glossary

There are a number of terms that you may hear or read when shopping for or learning about stone tile. Here's a list of some of the most common words, and their definitions, that should make the entire process easier for you.

Acid-Washed Finish - A shiny finish with small etching marks (pits in the surface). This finish shows fewer scratches and is much more rustic in appearance than a honed finish. Most stones can be acid-washed but the most common are marble and limestone. Acid washing is also a way to soften the shine on granite.

Agglomerate Stone - see Manufactured Stone.

Brushed Finish - A finish that features a worn-down look achieved by brushing the surface of the stone, simulating natural wear over time.

Bull Nose Edge - The rounded or curved edge of a stone tile.

Calibrated - A stage of the production of stone tile when the stone slab's surface is worked down to a relatively uniform thickness across the length of the material.

CBU - Cement Backer Unit. Wood subfloors usually require a for support and a moisture barrier when installing stone tile.

Fabricator - The company that or facility where the natural stone slabs are customized for specific installations.

Flamed Finish - A finish achieved by heating the surface of the stone to extreme temperatures, followed by rapid cooling. The surface of the stone pops and chips leaving a rough, unrefined texture. This process is usually done with granite. Flamed granite has a highly textured surface, making it ideal for areas where slip resistance might be a concern, like shower areas.

Granite - An igneous stone that is extremely hard, dense and resistant to scratches and acid etching. It is an ideal stone for use in flooring and in food preparation areas. Hundreds of varieties of granite exist.

Grout - A type of cement that is used to fill the space and provide support in tile joints.

Honed Finish - A finish that provides a flat, matte or satin finish, creating a more informal and softer look. This finish is created by stopping short of the last stage of polishing. A honed finish shows fewer scratches, and requires very little maintenance.

Igneous Rock - Rock formed when molten rock (called lava or magma) cools and hardens. Granite is an example of an igneous rock.

Limestone - A sedimentary stone formed from calcite and sediment. Limestone comes in many earthen colors.

Manufactured Stone (also known as Agglomerate Stone) - A synthetic stone made from natural stone chips suspended in a binder such as cement, epoxy resins or polyester. Some of the most popular types of manufactured stone products are those made mostly of quartz. The natural quartz gives the product depth and radiance while at the same time strength and consistency. Manufactured Stone is strong, it has four times the flexural strength of granite, therefore less chipping or cracking. The most well known agglomerated stone is poured-in-place terrazzo, used in building for thousands of years.

Marble - A derivative of limestone. It is a metamorphic stone that can be polished. Marble is characteristically soft and easily scratched or etched by acids. There are countless types of marble from around the world.

Metamorphic Rock - Rock created when other kinds of rocks are changed by great heat and pressure inside the earth. Marble, slate and quartzite are examples of metamorphic rocks.

Polished Surface Finish - A polished surface creating a beautiful glossy shine from the natural reflection of the stone's crystals. The mirror-like shine is accomplished by using progressively finer polishing heads during the polishing process.

Porosity - The amount and size of the pores in a stone. Travertine is very porous and granite is not.

Quarry - Massive rock deposits. For millions of years, a combination of heat and pressure created blocks of natural stone. As the earth's crust began to grow and erode, it pushed minerals up from its core, to form quarries.

Sandstone - A sedimentary stone that is primarily composed of loose grains of quartz sand that are rough in texture. A number of varieties are available.

Saw-Cut Refined Finish - This stone finish offers a matte finish. After initial cutting, the stone is processed to remove the heaviest saw marks but not enough to achieve a honed finish. You can purchase granite, marble and limestone this way, typically on a special order basis.

Sedimentary Rock - Rock formed from biological deposits that have undergone consolidation and crystallization. Limestone and sandstone fall into this category.

Slab - Block of stone that have been extracted from the earth and cut.

Slate - A metamorphic stone that has a sheet-like structure. It is composed of clay, quartz and shale, and comes in a multitude of colors including reds and greens.

Split-Faced Finish - A stone finish that creates a rough texture, but one not as abrasive as flamed. This finish is typically achieved by hand cutting and chiseling at the quarry, exposing the natural cleft of the stone. This finish is primarily done on slate.

Stone Tile - The typical natural stone floor tile sizes are 12" x 12", 13" x 13", 16" x 16" and 18" x 18".

Straight 90-Degree Edge - The square corner edge of a stone tile, creating a more modern and clean look.

Substrate - The surface on which the stone tile is laid.

Thinset - A cement based adhesive that is applied to the surface with a notched or grooved trowel. The tile is then placed into the thinset and pressed firmly into place. Since stone tiles vary in thickness and size, the amount of thinset mortar applied is adjusted where needed.

Travertine - A crystallized, partially metamorphosed limestone which, because of its structure, can be filled and honed and is dense enough to be a type of marble.

Tumbled Finish - A stone finish that delivers a smooth or slightly pitted surface, and broken, rounded edges and corners. Marble and limestone are primary candidates for a tumbled finish.

Unsanded Grout - Grout that does not contain sand. In most cases unsanded grout is a dry, Portland cement-based product that is mixed with water onsite. Grout is a type of cement that is used to fill the space and provide support in tile joints. Unsanded grout is most commonly used in natural stone installations because it is able to fill the small joints more easily and will not scratch soft stones like sanded grout.