Hard Surface Glossary

Agglomerates – Pieces of marble are mixed together with resins to form a block slab, which is then cut and finished. Agglomerates look like natural stone, and come in a variety of colors.

Black Marble – Such as Negro Marquina. This is a very soft limestone often mistaken as a marble. Not recommended for interior flooring.

Cultured or Faux Marble – A mix of resins and powdered marble or granite with a gel coat on the surface to look like marble.

Granite – Very dense, hard and brittle granite stands up well against heavy foot traffic, making it preferable for commercial lobby floors and walkways. True granite is the hardest of the polished stones commercially available and is used in high stress situations. Resistant to most chemicals, except for oils, which can permeate the stone, granite is also ideal for counters and bar tops. Composed of quartz and feldspar, granite should be sealed with an oil-repellant penetrating sealer to prevent staining and reduce soiling. Flamed granite surfaces are very absorbent due to the stress fractures in the stone caused by the flaming process and should be sealed to maintain the original color and appearance of the stone over time. Do not try to polish or hone. NOTE: Some stone marked and sold as “granite” are marble instead – always do an acid resistance test to confirm. Some granite is dyed! Not etched by most acids, but can be etched by hydrofluoric acid!

Marble – Available in a wide range of colors, marble is often used for its beauty, but is more porous, softer, and chemically sensitive than granite. Marble floors and countertops show wear sooner than granite, but can be restored with honing and polishing more easily. Marble can be etched by acids, including soft drinks. Marble absorbs oils and other liquids and is easily stained. Composed of Calcite and Calcium Carbonate, marble should be sealed with a penetrating sealer to prevent staining and reduce soiling. Marble should only be cleaned with neutral pH detergents.

Limestone – Many older buildings have durable limestone flooring. This is the chalky porous type typical of most French and Spanish limestone. Limestone can be etched by acids, including soft drinks. Limestone absorbs oils and other liquids and is more easily stained than marble. Limestone is composed of Calcite and some Magnesium. Common colors include black, gray, white, yellow and brown. It has a smooth granular surface and varies in hardness. Limestone should be sealed with a penetrating sealer to prevent staining and reduce soiling. Clean only with neutral pH detergents.

Mexican Tile/Terra-cotta/Saltillo – The word Terra-cotta comes from Italian terra, ‘earth’, and cotta, ‘cooked’ – a hard-baked, brownish red earthen ware, often glazed and colored. Usually hand-made and varies in color, texture and appearance. Mexican tile may come prefinished or require application of various types of sealers or coatings on site to provide a wearing surface. It may crumble or show wear quickly unless sealed and laid on a waterproof layer. Saltillo is often custom colored with a stain that can wear off or be harmed. Saltillo is very porous. Efflorescence is common with saltillo tile.

Porcelain Tile – is an unglazed ceramic tile that is generally made from a composition which results in a tile that is dense, impervious, fine grained and smooth, with a sharply formed face. Porcelain tile is available in matte, unglazed or a high polished finish. Porcelain tile has the same hard fired material and color all through the body.

Quarry Tile – A glazed or unglazed tile made by the extrusion process from natural clay or shale. This tile is most common in the dark red shades; however, shades of brown and gray are also available. Quarry tile has the same hard fired material and color all through the body.

Sandstone – is a formation of quartz grains. Sandstone should be sealed and regularly maintained because it so easily absorbs stains.

Slate – is a very dense, but soft and easily scratched material with low porosity, slate can be used effectively outdoors as well as indoors. Slate makes an excellent exterior paving stone. Higher absorbency varieties are not suitable for exterior areas in freezing climates. Composition: Mainly grains of mica and quartz, plus smaller amounts of chlorite, hematite, and other minerals. Most slate is gray to black, but the rock may be red or purple, depending on its mineral content. The surface of slate is generally uneven and cleft planes can spall, due to the cleaving of the stone along its layers. Slate has low to medium absorption of oils and other liquids. Slate floors should be sealed with an oil-repellant penetrating sealer to prevent staining and reduce soiling.

Soapstone – also known as steatite, is a metamorphic rock. It tends to be a very soft rock. There are two different kinds of stone, popularly called soapstone: Talc, which is a softer stone, used for carvings, and Steatite, which is harder than Talc, used for countertops, fireplaces, ovens and other uses.

Serpentine – is not a rock, but a group of minerals composed primarily of hydrated magnesium silicate that is green, yellow, or brown in color. It gets its name due to the resemblance to a serpent’s skin. Many so-called green marbles are actually serpentines, not marbles. Pure serpentine is not acid sensitive, therefore there is no etching. Be careful here – not all greens are pure serpentine. Some lighter greens, like Spring Green, have some carbonate mixed in, and will react to acid. Also, there are greens that are true marbles such as Verde Antigua and Cippolino. Very sensitive to water – must be set in epoxy or waterless setting mortars to prevent warping. Will develop small white spalls from salt deposits. Do not try to polish or hone.

Terrazzo – is a type of agglomerate flooring and should be treated as marble in a maintenance program. Terrazzo is etched by acids. Terrazzo does not need protection from wear – it needs protection from absorption and stains. A water based impregnator should be applied soon after honing and/or polishing. The impregnator is absorbed into the cement matrix, sealing its pores. It is important that the terrazzo is cleaned before the sealer is applied. Terrazzo floors should be cleaned only with a neutral pH cleaner.

Terrazzo Tile – Pre-manufactured consisting of marble or granite chips in a portland cement or epoxy matrix in various thicknesses and sizes.

Travertine – A type of limestone, travertine can be left in its natural state, with no polishing. Travertine is etched by acids. Porous with many visible holes, often filled with epoxy. Travertine can be polished to a shine.

There are four basic types of grout – sanded lime-based cementitious, lime-based cementitious unsanded, sanded epoxy-based and unsanded epoxy base.

Unsanded grout is typically paired with softer stones such as marble and limestone. Sanded grout is usually used with harder surfaces. You cannot hone and polish if sanded grout has been used with soft stone. Epoxy grout does not need to be sealed because it will not absorb moisture. Epoxy grout is commonly used in restaurant chains. Original grout color is very difficult to maintain with common tile cleaning products. Grout gets dirty and needs to be sealed. Grout in countertops gets ugly and unhealthy and needs to be cleaned and sealed. A heavy duty alkaline cleaner and degreaser, should be used to remove greasy soil from stone and tile floors, kitchen counters, bathroom shower stalls, and other natural stone and ceramic tile surfaces. Always test first!