Commonly used Natural Stone terms.

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Here is a quick reference to some commonly used words in stone business.

- A -

Abrasive finish: a flat non-reflective surface finish for marble.
Agate: a variegated variety of quartz showing colored bands or other markings.
Arch: a curved stone structure resting on supports at both extremities used to sustain weight, to bridge or roof open space.
Architrave: the member of an entablature resting on the capitals of columns and supporting the frieze.
Argillite: a compact sedimentary rock composed mainly of clay and aluminum silicate minerals.
Arris: a natural or applied line on the stone from which all leveling and plumbing is measured.
Ahslar – masonry having a face of square or rectangular stones, either smooth or textured. Return to Top

- B -

Back arch: a concealed arch carrying the backing of a wall where the exterior facing is carried by lintel.
Backsplash: the area located between the countertop and cabinets normally 4-18 inches high.
Baluster: a dense textured (aphanitic), igneous rock relatively high in iron and magnesia minerals and relatively low in silica, generally dark gray to black and feldspatic; a general term in contradistinction to felsite.
Bed: In granites and marbles, a layer or sheet of the rock mass that is horizontal, commonly curved and lenticular, as developed by fractures. Sometime applied also to the surface of parting between sheets.
Bluestone: a dense, hard, fine-grained, commonly feldspatic sandstone or siltstone of medium to dark or bluish-gray color that splits readily along original bedding planes to form thin slabs, Bluestone is not a technical geologic term. It is considered to be a variety of flagstones, the thin relatively smooth-surfaced slabs being suitable for use as flagging. The term has been applied particularly to sandstone of Devonian age that is being or has been quarried in eastern New York and Pennsylvania and in western New Jersey, but similar stones that occur elsewhere may be included. It has also been applied in places to thinly layered gneisses and schist that can be split and used as flagging, but such stones are not properly embraced by this definition although they may be marketed properly as flagstone.
Brick pattern: a method of setting rectangular tiles in an offset fashion creating the look of brick.
Brushed finish: a finish resulting from treating the stone surface with a coarse wire rotary brush. Surface with brushed finish may have a soft, leathering appearance.
Border stone: usually a flat stone used as an edging material. A border stone is generally used to retain the field of the terrace of platform.
Brownstone: sandstone of characteristic brown or reddish-brown color that is due to a prominent amount of iron oxide, as interstitial material.
Building stone, natural rock: rock material in its natural state of composition and aggregation as it exists in the quarry and is usable in construction as dimension building stone.
Bull nose: convex rounding of a stone member, such as countertop edge. Return to Top

-C-

Calibrated Tile: stone tile that has been machine cut on both sides and has consistent thickness.
Calcarenite: limestone composed predominantly of classic sand-size grains of calcite, or rarely aragonite, usually as fragments of shells or other skeletal structures. Some contain oolites (small, spherical grains of calcium carbonate that resemble roe) and may be termed oolite limestone. Calcareous sandstone, in which the calcium carbonate is present chiefly as bonding material, are not included in this category.
Calcite limestone: a limestone containing not more than five percent of magnesium carbonate.
Calcite streaks: description of a white or milky-like streak occurring in stone. It is a joint plane usually wider than a glass seam and has been re-cemented by deposition of calcite in the crack and is structurally sound.
Carve: shaping, by cutting a design to form the trade of a sculptor.
Caulking: making a joint tight or leak-proof by sealing with an elastic adhesive compound.
Cement putty: a thick, creamy mixture made with pure cement and water, which is used to strengthen the bond between the store and the setting bed, also called cement butter cement cream.
Chat-sawn finish: a rough gang saw finish produced by sawing with coarse chat.
Chiseled Edge: edge of the stone that has been mechanically chipped. Stone with chiseled edge have a rustic aged appearance.
Cladding: non-load bearing stone used as the facing material in wall construction that contains other materials.
Cleavage: the ability of a rock mass to break along natural surfaces; a surface of natural parting.
Cleft finish: finish obtained by the method of splitting stone along its natural plane. This finish is normally found in slate.
Coating, Sealing: a protective or decorative converting applied to the surface or impregnated into stone for such purposes as waterproofing enhancing resistance to weathering, wear, and chemical action, or improving appearance of the stone.
Cobblestone: a natural rounded stone, large enough for use in paving; commonly used to describe paving blocks, usually granite, generally cut to rectangular shapes.
Commercial marble: a crystalline rock composed predominantly of calcite dolomite and/or serpentine, and capable of taking a polish.
Coquina: limestone composed predominantly of unaltered shells or fragments of shells loosely cemented by calcite, generally very coarse-textured with a high porosity. The term has been applied principally to a very porous shell rock of Eocene age that has been quarried in Florida.
Corbel plates: plates of non-ferrous metal fixed into a structure to support stone cladding at intervals and over opening in such a way as not to be visible.
Cornerstone: a stone forming a part of a corner or angle in a wall. Also a stone laid at the formal inauguration of the erection of a building, not necessarily at a corner, usually incorporating a date or inscription.
Crack: a break, split, fracture, fissure, separation, cleavage or elongated narrow opening, however caused, visible without magnification to the human eye and extending from the surface into the stone that must extend through the grain or matrix.
Cross-cut: stone that has been cut from the stone block parallel to the natural bedding plane. Cross-cut stone has a mottled or cloudlike appearance.
Crowfoot: description of a dark gray to black zigzag marking occurring in stone. Usually structurally sound.
Crystalline limestone – a limestone, either calcite or dolomite, composed of interlocking crystalline grains of the constituent minerals and of phaneritic texture; commonly used synonymously with marble an thus representing a re-crystallized limestone; improperly applied to limestone that display some obviously crystalline grains in a fine-grained mass but which are not of interlocking texture and do not compose the entire mass.
Curbing: slabs and blocks of stone bordering streets, walks, etc.
Cutting stock: a term used to describe slabs of varying size, finish and thickness which are used in fabricating tread, risers, copings, borders, sills, stools, hearths, mantels, and other special purpose stones. Return to Top

- D-

Damp proofing: one or more coating of a compound that is impervious to water applied to a surface above grade.
Defect: those features, which affect or have the potential of affecting the structural soundness of building stone, or may affect the durability of the building stone. Sometimes used for visual features such as xenoliths or veins.
Dolomite limestone: a limestone rich in magnesium carbonate, frequently somewhat crystalline in character, found in ledge formations in a wide variety of color tones and textures. Generally speaking, it’s crushing and tensile strengths are greater than the oolitic limestone and its appearance shows greater variety in
Dry wall: a dry wall is a stone wall that is constructed one stone upon the other without the use of any mortar. Generally used for retaining walls.
Durability: the measure of the ability of natural building stone to endure and to maintain its essential and distinctive characteristics of strength, resistance to decay, and appearance, with relation to a specific manner, purpose, and environment of use. Return to Top

- F -

Face: this refers to the exposed portion of stone. The word "face" can also be used when referring to the edge treatment on various cutting stock materials.
Field stone: loose blocks separated from ledges by natural processes and scattered through or upon the regolith ("soil") cover, applied also to similar transported materials, such as glacial boulders and cobbles.
Filled stone: stone with the pores that have been pre filled with a stone dust resin or epoxy. Commonly found in travertine.
Fines: the powder, dust, silt-size and sand-size material resulting from processing (usually crushing) rock.
Finished stone: building stone with one or more mechanically dressed surfaces.
Fireproof: heat resistant, relatively incombustible.
Flagstone: thin slabs of stone used for flagging or paving walks, driveways, patios, etc. It is generally fine-grained sandstone, bluestone, quartzite or slate, but thin slabs of other stones may be used.
Flamed finish: A rough textured surface achieved through exposure to heat and flame. Popular granite surface finish.
Fleuri cut: cutting quarried marble or stone parallel to the natural bedding plane.
Fracture: a break in rock produced by mechanical failure. Fractures include faults and joints. Return to Top

- G -

Gangs awed: description of the granular surface of stone resulting from gangs awing alone.
Gauged or gauging: a grinding process to make all pieces of material to be used together the same thickness.
Grain: the easiest cleavage direction in a stone. "With the grain" same as "natural bed." Also, particles (crystals, sand grains, etc.) of rock.
Granite: a fine to coarse-grained, igneous rock formed by volcanic action consisting of quartz, feldspar, and mica, with accessory minerals. Granite-type rocks included those of similar texture and origin.
Greenstone: includes stone that have been metamorphosed or otherwise changed so that they have assumed a distinctive greenish color owing to the presence of one or more of the following minerals: chlorite, epidote, or actinolite.
Grout: A cement like or epoxy based material used to fill gaps and joints between tiles. Return to Top

- H -

Head: the end of a stone that has been tooled to march the face of the stone. Heads are used at outside corners, windows, doorjambs, or any place where the veneering will be visible from the side.
Hearth stone: originally the single large stone or stones used for the hearth, now most commonly used to describe the stone in of the fire chamber and many times extending on either or both sides of the front of the fire chamber.
Herringbone pattern: A method of setting rectangular tiles slanted, creating a zigzag effect
Honed finish: honed is a super fine smooth finish, thought not as fine as a polished finish. Return to Top

- I -

Igneous: one of the three great classes of rock (igneous, sedimentary and metamorphic) solidified from molten state, as granite and lavas.
Inscription: lettering cut in stone.
Inserts: Decorative tiles or accent pieces that can be inserted into the area where the four tiles meet, or placed in the center of a tone tile. Return to Top

- L -

Lava: a general term applied to igneous rock’s, such as basalt and rhyolite, that erupted from the earth by volcanic action.
Limestone: a sedimentary rock composed of calcium carbonate; includes many varieties (see oolitic limestone, dolomitic limestone, and crystalline limestone.) Limestone that contains not more than five per cent magnesium carbonate may be termed calcite limestone, as distinguished from those that contain between five and 40% as the mineral dolomite (dolostone, formerly known as the rock dolomite). Re crystallized limestone and compact, dense, relatively pure microcrystalline varieties that are capable of taking a polish are included in commercial marbles.
Liners: structurally sound sections of marble that are cemented to the back of marble veneer slabs to give greater strength, additional bearing surface, or to increase joint depth. Return to Top

- M -

Machine finish: literally, badlands; refers to dark-colored rock, commonly lava, in rough terrain. As defined for architectural use: calcium carbonate with other components which give it color, markings and texture suitable as a desirable building stone.
Marble: a metamorphic (re crystallized limestone composed predominantly of crystalline grains of calcite or dolomite, or both, having interlocking or mosaic texture, marble that contains less than 5% magnesium carbonate may be termed calcite marble; from 5 to 40 % magnesium carbonate, magnesium carbonate, magnesium or dolomite marble. These limiting values are, however, not strictly established in petrologic science and are used herein as arbitrary limits.
- Onyx: so called in trade, is a crystalline form, commonly micro crystalline, of calcium carbonate deposited usually from cold-water solutions. It is generally translucent and shows a characteristic layering, the term onyx marble is technically a misnomer, as true onyx is a variety of crypto crystalline fibrous silica (chalcedony), and is closely related in form and origin to agate.
- Serpentine: marble characterized by a prominent amount of the mineral serpentine.
- Travertine: a form of limestone precipitated from ground waters as in caves or in orifices of springs (sees limestone).
- Verde antique: a commercial marble composed chiefly of massive serpentine and capable of taking a high degree of polish. Verde antique is not a true marble in the scientific sense but is commonly sold as a decorative commercial marble and requires the adjective modifier Verde (or verd) antique. Verde antique is commonly veined with carbonate minerals, chiefly calcite and dolomite.
Metamorphism: the change or alteration in a rock cause by exterior agencies such as deep-seated heat and pressure, or intrusion or rock materials. Return to Top

- N -

Non-Staining mortar: Mortar composed of materials which individually or collectively do not contain material that will stain, usually having very low alkali content. Return to Top

- O -

Obsidian: a glassy phase of lava.
Onyx marble: A dense, crystalline form of lime carbonate deposited usually from cold-water solutions. Generally translucent and showing a characteristic layering due to mode of accumulation. Return to Top

- P -

Paving: Stone used as an exterior-wearing surface, as in patios, walkways, driveways, etc.
Pillowed edge: An edge that is soft and rounded.
Pitched stone: Stone having arris clearly defined; face, however, is roughly cut with pitching chisel used along the line that becomes the arris.
Plucked finish: Obtained by rough-planning the surface of stone, breaking or plucking out small particles to give rough texture.
Polished finish: A shiny, glossy finish achieved by polishing on hard stones (granite, marble). Polished finish draws out the deepest color of the stone. Return to Top

- Q -

Quarry: The location of an operation where a natural deposit lf stone is removed from the ground.
Quartz: A silicon dioxide mineral that occurs in colorless and transparent or colored hexagonal crystals and also in crystalline masses. One of the most common minerals, the chief constituent of sandstone.
Quartzite: A compact granular rock composed of quartz crystals, usually so firmly cemented as to make the mass homogenous. The stone is generally quarried in stratified layers, the surfaces of which are unusually smooth. Its crushing and tensile strengths are extremely high; the color range is wide.
Quartz sandstone: A sandstone with a high concentration of quartz grains and siliceous cement. Return to Top

- R -

Rock: an integral part of the earth’s crust composed of an aggregate of grains of one or more minerals. (Stone is the commercial term applied to quarry products.)
Rock (pitch) face: similar to split face, except that the face of the stone is pitched to a given line and plane producing a bold appearance rather than the comparatively straight face obtained in split face. Return to Top

- S -

Sandblasted: a matte-texture marble surface finish with no gloss, accomplished by exposing the surface to a steady flow of sand under pressure.
Sand-sewn finish: the surface left as the stone comes from the gang saw; moderately smooth, granular surface varying with the texture and grade of the stone.
Sandstone: a sedimentary rock consisting usually of quartz, cemented with silica, iron oxide or calcium carbonate, Sandstone is durable, has a very high crushing and tensile strength and a wide range of colors and textures. Varieties of sandstone are commonly designated by the kind and prominence of interstitial and bonding material, as siliceous sandstone (bonding material primarily silica), calcareous sandstone (calcium carbonate prominent as bonding material or as accessory grains or both), sandstone (clay minerals prominent as interstitial or bonding materials, or as thin laminate ferruginous sandstone (iron oxide or hydroxide minerals (hematite,, limonite, et al) as interstitial or as boding materials in sufficient amount to impart appreciable color of stone); brownstone (ferruginous sandstone of dark brown or reddish brown color), arkose, arkosic sandstone, or feldspatic sandstone (a sandstone that contains an abundance of grains of feldspar), conglomerate a sandstone composed in large part of rounded pebbles, also called pudding stone).
Sawed edge: a clean-cut edge generally achieved by cutting with a diamond blade, gang saw or wire saw.
Sawed face: a finish obtained from the process used in producing building stone; varies in texture from smooth to rough and coincident with the type of materials used in sawing; characterized as diamond sawn, sand sawn, chat sawn and shot sawn.
Sculpture: the work of a sculptor in three-dimensional form by cutting from a solid block of stone.
Shot-sawn: description of a finish obtained by used steel shot in the gangs awing process to produce random markings for a rough surface texture.
Slab: A lengthwise cut of a large quarry block of stone produced by sawing or splitting in the first milling or quarrying operation. A slab has tow parallel surfaces.
Slate: A very fine grained metamorphic rock derived from sedimentary rock shale. Characterized by an excellent parallel cleavage entirely independent of original bedding, by which cleavage the rock may be split easily into relatively thin slabs.
Soapstone: a massive variety of talc with a soapy or greasy feel used for hearths, washtubs, tables tops, carved ornaments, chemical laboratory counter, etc., and known for its stain-proof qualities.
Split stone finish: obtained by sawing to accurate heights then breaking by machine to required bed widths. (Normal bed widths are 3 ½ inches (90 mm).
Stone: sometimes synonymous with rock, but more properly applied to individual blocks, masses or fragments taken from their original formation or considered for commercial use. Return to Top

- T -

Template: a pattern for repetitive marking or fabricating operation.
Travertine limestone: a variety of limestone that has a partly crystalline or microcrystalline texture and porous or cellular layered structure, the cells being usually concentrated along certain layers and commonly displaying small stalactitic forms.
Travertine marble: a variety of limestone regarded as a product of chemical precipitation from hot springs. Travertine is cellular with the cells usually concentrated in thin layers that display a stalactitic structure. Some that take a polish are sold as marble and may be classified as travertine marble under the class of commercial marble.
Tumbled: A finish achieved by placing stone tiles in a tumbling machine or drum, sometimes with the addition of acids, to soften the edges and give the surface a time-worn look. Return to Top

- U -

Unfilled: stone surface with pits and holes that have not been filled. Commonly associated with travertine. Return to Top

- V -

Vein cut: Stone that has been cut off the stone block perpendicular to the natural bedding plane. Vein cut stone has enhanced horizontal vein structure.
Veining: colored markings in limestone, marble, alabaster, etc.
Verde antique: a marble composed chiefly of massive serpentine and capable of being polished. It is commonly crossed by vein lets of other minerals, chiefly carbonates of calcium and magnesium. Return to Top

- W -

Wire saw: method of cutting stone by passing a twisted, multi-strand wire over the stone and immersing the wire in slurry of abrasive material. Return to Top