Brush Up on Your Natural Stone Knowledge

A

• abrasive finish – a flat non-reflective surface finish for marble.
• abutment – a solid stone “springer” at the lowest point of an arch or vault.
• adhered – veneer secured and supported through adhesion to an approved bonding material applied over an approved backing.
• agate – a variegated variety of quartz showing colored bands or other markings (clouded, mosslike, etc.).
• anchors – types of stonework include those made of flat stock (strap, cramps, dovetails, dowel, strap and dowel, and two-way anchors) and round stock (rod cramp, rod anchor, eyebolt and dowel, flat-hood wall tie and dowel, dowel and wire toggle bolts).
• apex stone – uppermost stone in a gable, pediment, vault or dome.
• arch – a curved stone structure resting on supports at both extremities used to sustain weight, to bridge or roof an 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.
• arkose – a sandstone containing 10% or more clastic grains of feldspar. Also called arkosic sandstone, feldspathic sandstone.
• arris – a natural or applied line on the stone from which all leveling and plumbing is measured.
• ashlar – stones basically rectangular in shape and exhibiting the split face of the stone revealing striations that can be quite colorful.

B

• back arch – a concealed arch carrying the backing of a wall where the exterior facing is carried by a lintel.
• baluster – a miniature pillar or column supporting a rail, used in balustrades.
• balustrade – an ornamental fencing consisting of a series of balusters supporting a handrail or molding.
• banker – bench of timber or stone on which stone is shaped.
• basalt – a dense-textured (aphanitic), igneous rock relatively high in iron and magnesia minerals and relatively low in silica, generally dark grey to black, and feldspathic; a general term in contradistinction to felsite, a light-colored feldspathic and highly siliceous rock of similar texture and origin.
• bed – the top or bottom of a joint, natural bed; surface of stone parallel to its stratification. (1) In granites and marbles, a layer or sheet of the rock mass that is horizontal, commonly curved and lenticular as developed by fractures. Sometimes applied also to the surface of parting between sheets. (2) In stratified rocks the unit layer formed by semidentation; of variable thickness, and commonly tilted or distorted by subsequent deformation; generally develops a rock cleavage, parting, or jointing along the planes of stratification.
• belt course – a continuous horizontal course of flat stones placed in line marking a division in the wall plane.
• bevel – when the angle between two sides is greater or less than a right angle.
• bluestone – a dense, hard, fine-grained, commonly feldspathic 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 flagstone, the thin relatively smooth-surfaced slabs being suitable for use as flagging. The term has been applied particularly to sandstones of Devonian age that are being or have 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 schists 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.
• bond stone – used in varying percentages to anchor or bond the stone veneer to the backing material. Bond stones are generally cut to twice the bed thickness of the material being used. border stone – usually a flat stone used as an edging material. A border stone is generally used to retain the field of the terrace or platform.
• box – a tapered metal box wedged in the top of columns or other heavy stones for hoisting.
• broach – to drill or cut out material left between closely spaced drill holes; a mason’s sharp-pointed chisel for dressing stone; an inclined piece of masonry filling the triangular space between the base of an octagonal spire and the top of a square tower; a type of chisel used for working narrow surfaces.
• brownstone – a sandstone of characteristic brown or reddish-brown color that is due to a prominent amount of iron oxide, as interstitial material.
• brushed finish – obtained by brushing the stone with a coarse rotary-type wire brush.
• building stone, natural – 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 a stair tread.
• buttering – placing mortar on stone with a trowel before setting into place.

C

• calcarenite – limestone composed predominantly of clastic sand-size grains of calcite, or rarely aragonite, usually as fragments of shells or other skeletal structures. Some calcarenites contain oolites (small, spherical grains of calcium carbonate that resemble roe) and may be termed oolite limestone. Calcareous sandstones, 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 5% 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.
• canopy – a sheltering roof, as over a niche or a doorway.
• capital – the culminating stone at the top of a column or pilaster, often richly carved.
• carve – shaping, by cutting a design to form the trade of a sculptor.
• caulking – making a marble joint tight or leak-proof by sealing with an elastic adhesive compound.
• cavity vent – a vent or opening in the joints between stones to provide even atmospheric pressure and humidity between the cavity and outside air; to prevent condensation and the migration of water into the structure.
• cement putty-cream-butter – a thick creamy mixture made with pure cement and water which is used to strengthen the bond between the stone and the setting bed.
• chamfer – to bevel the junction of an exterior angle.
• chat-sawn finish – a rough gangsaw finish produced by sawing with coarse chat.
• cladding – non-load-bearing thin stone slabs used for facing buildings.
• cleavage – the ability of a rock mass to break along natural surfaces; a surface of natural parting.
• cleavage plane – plane or planes along which a stone may likely break or delaminate.
• coating – a protective or decorative covering 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 one or more of the following materials: calcite dolomite or serpentine, and capable of taking a polish.
• composite – a construction unit in which stone that is to be exposed in the final use is permanently bonded or joined to other material, which may be stone manufactured material, that will be concealed.
• conglomerate – gravel that has been cemented together with silica, iron oxide or calcium carbonate.
• contraction joints – spaces where panels are joined and which expand as the panels contract.
• control joint – provided so that the movement of different parts of the structure due to shrinkage, expansion, temperature changes or other causes do not transfer loads across the joint.
• coping – a flat stone used as a cap on freestanding walls.
• coquina – a limestone composed predominantly of unaltered shells or fragments of shells loosely cemented by calcite. Coquina is generally very coarse-textured and has a high porosity. The term has been applied principally to a very porous shell rock of Eocence 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 openings 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.
• cornice – a molded projecting stone at the top or an entablature.
• course – a horizontal range of stone units the length of the wall.
• coursed veneer – this is achieved by using stones of the same or approximately the same heights. Horizontal joints run the entire length of the veneered area. Vertical joints are constantly broken so that no two joints will be over one another.
• 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-bedding – the arrangement of laminations of strata transverse or oblique to the main planes of stratification.
• crowfoot (styolite) – description of a dark gray to black zigzag marking occurring in stone. Usually structurally sound.
• crystalline limestone – a limestone, either calcitic or dolomitic, composed of interlocking crystalline grains of the constituent minerals and of phaneritic texture; commonly used synonymously with marble and thus representing a recrystallized limestone; improperly applied to limestones 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. (NOTE: All limestones are microscopically, or in part megascopically, crystalline, the term is thus confusing but should be restricted to stones that are completely crystalline and of megascopic and interlocking texture and that may be classed as marbles).
• curbing – slabs and blocks of stone bordering streets, walks, etc.
• cut stone – this includes all stone cut or machined to give sizes, dimension or shape, and produced in accordance with working or shop drawings which have been developed from the architect’s structural drawings.
• cutting stock – a term used to describe slabs of varying size, finish, and thickness which are used in fabrication treads, risers, copings, borders, sills, stools, hearths, mantels, and other special purpose stones.

D

• dacite – a fine-grained, extrusive (volcanic) rock, intermediate in color and composition between basalt and rhyolite
• damp-proofing – one or more coatings 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.
• dentil – block projections on an entablature.
• dentil course – the lower part of the cornice with dentils. The cornice is jointed to allow machines production of the dentils.
• dentils – small, rectangular blocks under a classical cornice, resembling a row of teeth.
• dimensional stone – quarried stones, generally two feet or more square, of a specified thickness. Usually with one or more mechanically dressed surfaces.
• dolomitic 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, its crushing and tensile strengths are greater than the oolitic limestones and its appearance shows greater variety in texture.
• dowel – a short piece of non-ferrous metal or slate fixed into a mortise or sinking in the joints of adjoining stones to prevent movement.
• dressed or hand-dressed – the cutting of rough chunks of stone by hand to create a square or rectangular shape. A stone which is sold as dressed stone generally refers to stone ready for installation. Sometimes called scabbling.
• drip – a recess cut beneath and slightly behind projecting stone to prevent water from running down the face of the wall below.
• dripstone – a projecting moulding over the heads of doorways, windows and archways to throw off the rain. Also known as a “hoodmould” and, when rectangular, as a “label”.
• dry – an open or unhealed joint plane not filled with calcite and not structurally sound.
• 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 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.

E

• efflorescence – a crystalline deposit appearing on stone surfaces typically caused by soluble salts carried through or onto the stone by moisture, which has sometimes been found to come from brick, tile, concrete blocks, cement, mortar, concrete, and similar materials in the wall or above.
• entablature – in classical architecture, the upper part of an order, comprising architrave, frieze, and cornice.
• entasis – the curve of the upper two-thirds of a column.
• expansion bolt – a socket that grips a drilled hole in stone by expanding as the bolt is screwed into it.
• expansion-contraction joint – a joint designed to allow the expansion and contraction of a wall due to temperature change. An expansion joint compresses as panels expand, a contraction joint expands as panels contract. exposed aggregate – phrase applied to the larger pieces of stone aggregate purposefully exposed for their color and texture in a cast slab.

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.
• fascia – a horizontal belt or vertical face; often used in combination with moldings.
• ferruginous – limestone or sandstone containing a high proportion of iron oxide.
• fieldstone – loose blocks separated from ledges by natural process and scattered through or upon the regolith (“soil”) cover; applied also to similar transported materials, such as glacial boulders and cobbles.
• filling – filling the natural voids and veins in a stone with material (cement, shellac, or synthetic resins and similar materials often mixed with stone fines).
• fines – the residue resulting from the normal fabrication and processing of stone.
• finish – the final appearance exposed stone slab surfaces are fabricated to meet.
• finished stone – building stone with one or more mechanically dressed surface(s).
• fireproof – relatively incombustible.
• fissure – A visible separation along the crystalline boundaries naturally occurring in the stone.
• 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.
• fleuri cut – cutting quarried marble or stone parallel to the natural bedding plane.
• flooring – stone used as an interior pedestrian wearing surface.
• foliated – the layered, banded structure of rock.
• fracture – a break in rock produced by mechanical failure. Fractures include faults and joints.
• freestone – a stone that may be cut freely in any direction without fracture or splitting.
• frieze – a belt course, sometimes decorated with sculpture relief, occurring just under a cornice.

G

• gang sawed – description of the granular surface of stone resulting from gangsawing alone.
• gauged or gauging – a grinding process to make all pieces of material to be used together the same thickness.
• glass seam – a narrow glass-like streak occurring in stone; a joint plane that has been re-cemented by deposition of translucent calcite in the crack and is structurally sound.
• grade course – beginning course at the grade level, generally waterproofed with a dampcheck or damp course.
• grain – the easiest cleavage direction in a stone. “With the grain” same as “natural bed”. Also, particles (crystals, etc.) of a 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 include those of similar texture and origin.
• granite (scientific definition) – a visibly granular, crystalline rock of predominantly interlocking texture, composed essentially of alkalic feldspars and quartz; this is true granite. Feldspar is generally present in excess of quartz, and accessory minerals (chiefly micas, hornblende, or more rarely pyroxene) are commonly present. The alkalic feldspars may be present (1) as individual mineral species, (2) as isomorphous or mechanical intergrowths with each other, or (3) as chemical intergrowths with the lime feldspar molecule, but 80 + 3% of the feldspar must be composed of the potash or soda feldspar molecules.
• granite (commercial/building use) – a term that includes granite (as defined above), gneiss, gneissic granite, granite gneiss, and the rock species known to petrologists as syenite, monzonite, and granodiorite, species intermediate between them, the gneissic varieties and gneisses of corresponding mineralogic compositions and the corresponding varieties of porphyritic textures. The term commercial granite shall also include other feldspathic crystalline rocks of similar textures, containing minor amounts of accessory minerals, used for special decorative purposes, and known to petrologists as anorthosite and laurvikite.
• granite gneiss – a foliated crystalline rock composed essentially of silicate minerals with interlocking and visibly granular texture, and in which the foliation is due primarily to alternating layers, regular or irregular, of contrasting mineralogic composition. In general a gneiss is characterized by relatively thick layers as compared with a schist. According to their mineralogic compositions, gneisses may correspond to other rocks of crystalline, visibly granular, interlocking texture, such as those included under the definition of commercial granite, and may then be known as granite gneiss if strongly foliated, or gneissic granite if weakly foliated.
• black granite – rock species known to petrologists as diabase, diorite, gabbro, and intermediate varieties are sometimes quarried as building stone, chiefly for ornamental use, and sold as “black granite”. As dimension blocks or slabs, they are valued for their dark grey to black color when polished. Scientifically, they are far removed in composition from true granites though they may be used for some of the purposes to which commercial granites, are adapted. They possess an interlocking crystalline texture, but unlike granites, they contain little or no quartz or alkalic feldspar, and are characterized by an abundance of one or more of the common black rock-forming minerals (chiefly pyroxenes, hornblende, and biotite).
• granular – having a texture characterized by particles that are apparent to the unaided eye. For sedimentary rocks; particles less than 4 inches (10 mm) in diameter and approximately equal in size.
• greenstone – includes stones 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 – pourable cementitious material.
• coarse grout – used for wide grout spaces 2″ or more, consists of one part Portland cement, two-and-a-quarter to three parts sand, and one to two parts pea gravel.
• fine grout – used in narrow grout spaces, consists of one part Portland cement and two-and-a-quarter to three parts sand.

H

• hand-cut random rectangular ashlar – a pattern where all stone is hand cut into squares and rectangulars. Joints are fairly consistent. Similar to sawed-bed ashlar in appearance.
• hand or machine pitch-faced (rock-faced) ashlar – a finish given to both veneer stone and cutting stock. This is created by establishing a straight line back from the irregular face of the stone. Proper tools are then used to cut along the line, leaving a straight arris and the intended rustic finish on the face.
• head – the end of a stone which has been tooled to match the face of the stone. Heads are used at outside corners, windows, door jambs, or any place where the veneering will be visible from the side.
• hearth – that part of the floor of a fireplace of stone on which the fire is laid.
• hearth stone – originally the single large stone or stones used for the hearth, now most commonly used to describe the stone in front of the fire chamber and many times extending on either or both sides of the front of the fire chamber.
• holes – sinkages in the top beds of stone to engage Lewis pins for hoisting.
• honed finish – honed is a super fine smooth finish, though not as fine as a polished finish.
• hydrate – a mineral formed by the combination of water and some other elements or compounds.
• hydrothermal – of or relating to hot magnetic emanations that are rich in water.
• hydrous – containing chemically combined water.

I

• igneous – one of the three great classes of rock (igneous, sedimentary, and metamorphic), solidified from molten slate, as granite and lavas.
• incise – to cut inwardly or engrave, as in an inscription.
• inscription – lettering cut in stone.

J

• jack arch – one having horizontal or nearly horizontal upper and lower surfaces. Also called flat or straight arch.
• joint – the space between stone units, usually filled with mortar.
• jointing scheme – a detailed architectural drawing showing the dimensions, locations and configurations of stone units and joints on the structure.
• jumper – in ashlar patterns, a piece of stone of higher rise than adjacent stones which is used to end a horizontal mortar joint at the point where it is set.

K

keystone – the last wedge-shaped stone placed in the crown of an arch, regarded as binding the whole.

L

• lava – a general term applied to igneous rocks, such as basalt and rhyolite, that erupted from the earth by volcanic action.
• lead buttons – lead spacers in the solid horizontal joints to support the top stone until the mortar has set.
• lewis bolt – a tapered head wedged in a tapered recess in stone for hanging soffit stones.
• lewis holes – holes in cut stone for lifting and support during setting of cut stones and sometimes for permanent support. Holes are checked for the particular Lewis lifting device or hook to be used.
• limestone – a sedimentary rock composed of calcium carbonate; includes many varieties. (See oolitic limestone, dolomitic limestone, crystalline limestone). Limestones that contain not more than five per cent magnesium carbonate may be termed calcite limestone, as distinguished from those that contain between five and 40 per cent magnesium carbonate (magnesium or dolomitic limestone), and from those that contain in excess of 40 per cent as the mineral dolomite (dolostone, formerly known as the rock dolomite). Recrystallized limestones and compact, dense, relatively pure microcrystalline varieties that are capable of taking a polish are included in commercial marbles.
• liners – strengthening elements attached to the back of stone slabs, usually a structurally sound section of similar stone dowelled and epoxied into place.
• lintel – the block of stone spanning the top of an opening such as a doorway or window; sometimes called a head.
• lipping – usually refers to flagging materials; caused when two pieces of material to be joined together are slightly warped or twisted causing one or more edges to be higher or lower than the adjoining material.
• lug sill – a stone sill set into the jambs on each side of masonry openings.

M

• machine finish – the generally recognized standard machine finish produced by the planers.
• malpais – literally, badland; 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 limestone in a more or less crystalline state capable of taking a high polish. Occurs in a wide range of colors and variations. Marble that contains less than five percent magnesium carbonate may be termed calcite marble; from 5 to 40 percent magnesium carbonate, magnesian or dolomitic marble; and more than 40 percent 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 microcrystalline, of calcium carbonate deposited usually from cold water solutions. It is generally translucent and shows a characteristic layering. Onyx marble is technically a misnomer, as true onyx is a variety of cryptocrystalline fibrous silica (chalcedony), and is closely related in form and origin to agate.
• serpetine – 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 (see limestone group).
• 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 adjectival modifier verde (or verd) antique. Verde antique is commonly veined with carbonate minerals, chiefly calcite and dolomite.
• masonry – built up construction, usually of a combination of materials set in mortar.
• metamorphism – the change or alteration in a rock caused by exterior agencies, such as deep-seated heat and pressure, or intrusion of rock materials.
• miter – the junction of two units at an angle of which the junction lines usually bisect on a 45 degree angle.
• modular multiple-cut (pattern-cut) – this refers to standard patterns used throughout the stone industry. These patterns are usually based on multiples of a given height. Stone that is multiple cut or pattern cut is pre-cut to allow typically for ¼″ or ½″ (6 or 13 mm) joints or beds.
• moldings – decorative stone deviating from a plane surface by projections, curved profiles, recessed or any combination thereof.
• mortar – a plastic mixture of cement, lime, sand, and water used to bond masonry units.
• mosaic – a veneering which is generally irregular with no definite pattern. Nearly all the stone used in a mosaic pattern is irregular in shape.

N

• natural bed – the setting of the stone on the same plane as it was formed in the ground. This generally applies to all stratified materials.
• natural cleft – this generally pertains to stones which are formed in layers in the ground. When such stones are cleaved or separated along a natural seam the remaining surface is referred to as a natural cleft surface.
• nicked bit finish – obtained by planing the stone with a planer tool in which irregular nicks have been made in the cutting edge.
• non-staining mortar – mortar composed of materials which individually or collectively do not contain material that will stain, usually having a very low alkali content.

O

• obsidian – a glassy phase of lava.
• ogee – a stone profile with a reverse curved edge: concave above, convex below.
• onyx marble – a dense, crystalline form of lime carbonate deposited usually from cold water solutions. Generally translucent and shows a characteristic layering due to mode of accumulation.
• oolitic limestone – a calcite-cemented calcareous stone formed of shells and shell fragments, practically non-crystalline in character. It is found in massive deposits located almost entirely in Lawrence, Monroe and Owen Counties, Indiana and in Alabama, Kansas, and Texas. This limestone is characteristically a freestone, without cleavage planes, possessing a remarkable uniformity of composition, texture and structure. It possesses a high internal elasticity, adapting itself without damage to extreme temperature changes.
• opalized – the introduction into a rock of siliceous material in the form of opal, hydrous silicate.
• out of wind – to be out of wind is to have the arris of the stone not in parallel or perpendicular lines. Stone which is out of wind has an irregular or rustic appearance.

P

• palletized – a system of stacking stone on wooden pallets. Stone which comes palletized is easily moved and transported by modern handling equipment. Palletized stone generally arrives at the job site in better condition than unpalletized material.
• panel – a finished stone unit used on walls.
• parapet wall – that part of any wall entirely above the roof line.
• parging – plastering a cementitious coating of mortar onto a surface, often used for damp-proofing.
• parquetry – an inlay of stone floors in geometrical or other patterns.
• paving – stone used as an exterior wearing surface, as in patios, walkways, driveways, etc. (see flooring).
• perforated wall – wall containing a considerable number of relatively small openings. Often called pierced wall or screen wall.
• perrons – slabs of stone set on other stones serving as steps and arches in gardens.
• phenocryst – in igneous rocks, the relatively large and conspicuous crystals in a finer-grained matrix or ground mass.
• pilaster – an engaged pier of shallow depth; in classical architecture it follows the height and width of related columns, with similar base and cap.
• pitched stone – stone having arris clearly defined; face, however, is roughly cut with pitching chisel used along the line which becomes the arris.
• plinths – the lower square part of the base of a column. A square base or a lower block, as of a pedestal. The base block at the juncture of baseboard and trim around an opening.
• plucked finish – obtained by rough planing the surface of stone, breaking or plucking out small particles to give rough texture.
• pointing – the filling and tooling of mortar joints with mortar or caulking compounds.
• polished finish – the finest and smoothest finish available in stone characterized by a gloss or reflective property. Generally only possible on hard, dense materials.
• porphyry – an igneous rock in which relatively large and conspicuous crystals (phenocrysts) are set in a matrix of finer crystals.
• pressure relieving joint – an open horizontal joint below the supporting angle or hanger located at approximately every floor line and not over 15 feet (4.6 m) apart horizontally and every 20 to 30 feet (6 to 9m) vertically to prevent the weight from being transmitted to the masonry below. These joints are to be caulked with a resilient non-staining material to prevent moisture penetration.
• processing – the work involved in transforming building stone from quarry blocks to cut or finished stone. This includes primary sawing into slabs. It may also include both hand and mechanical techniques such as sawing, drilling, grinding, honing, polishing, and carving.
• projections – this refers to the pulling out of stones in a wall to give an effect of ruggedness. The amount of each stone is pulled out can vary between fi and 11/2 inches (1.3 to 3.8cm). Stones are either pulled out at the same degree at both ends or sometimes one end is pulled out, leaving the other end flush with the majority of veneer.
• pumice – and exceptionally cellular, glassy lava resembling a solid froth.

Q

• quarry – an excavation where usable stone is extracted 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 homogeneous. 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.
• quartzitic sandstone – a sandstone with a high concentration of quartz grains and siliceous cement.
• quirt – a groove separating a bed or other moulding from the adjoining members.
• quoins – stones at the corner of a wall emphasized by size, projection, rustification, or by a different finish.

R

• range – a course of any thickness that is continued across the entire face. All range course need not be of the same thickness.
• recess – a sinkage in a wall plane.
• reglet – a recess used to receive and secure flashing.
• relief or relieve – ornament in relief. The ornament or figure can be slightly, half, or greatly projected.
• relieving arch – one built over a lintel, flat arch or smaller arch to divert loads, thus relieving the lower member from excessive loading. Also known as discharging or safety arch.
• return – the right angle turn of a molding.
• return head – stone facing with the finish appearing on both the face and the edge of the same stone, as on the corner of a building.
• reveal – the depth of stone between its outer face and a window or door set in an opening.
• ribbon – narrow bands of rock differing to various degrees in chemical composition and color from the main body of the slate or stone; in other words, bands.
• rift – the most pronounced (see “grain”) direction of splitting or cleavage of a stone. Rift and grain may be obscure, as in some granites, but are important in both quarrying and processing stone.
• riprap – irregular shaped stones used for facing bridge abutments and fills. Stone thrown together without order to form a foundation or sustaining walls.
• rise – the word “rise” refers to the heights of stone. Generally used in reference to veneer stone.
• rock – the 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 – this is 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.
• rodding – reinforcement of a structurally unsound marble by cementing reinforcing rods into grooves or channels cut into the back of the slab.
• roman arch – semi-circular arch.
• rose window – a circular stone window fitted with carved tracery.
• rough sawn – a marble surface finish accomplished by the gangsawing process.
• rubbed finish – mechanically rubbed for smoother finish.
• rubble – a product term applied to dimension stone used for building purposes, chiefly walls and foundations, and consisting of irregularly shaped pieces, partly trimmed or squared, generally with one split or finished face, and selected and specified with a size range.
• rustication – chamfers or square sinkings around the face edges of individual stones to create shadows and to give an appearance of greater weight to the lower part of a building. When only the horizontal joints are sunk, the device is known as banded rustication.
• rustification – recessing the margin of cut stone so that when placed together a channel is formed at each joint.

S

• saddle – a flat strip of stone projecting above the floor between the jambs of the door; a threshold.
• sandblasted – a dull non-glossy finish applied to stone; usually achieved by blasting air blended with sand across the surface.
• sand-sewn finish – the surface left as the stone comes from the gangsaw. Moderately smooth, granular surface varying with the texture and grade of 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 materials, as siliceous sandstone (bonding material primarily silica), calcareous sandstone (calcium carbonate prominent as bonding material or as accessory grains or both), argillaceous sandstone (clay minerals prominent as interstitial or bonding materials, or as thin laminac), ferruginous sandstone (iron oxide or hydroxide minerals, or as thin laminac), ferruginous sandstone (iron oxide or hydroxide minerals {hematic, limonite, et al} as interstitial or as bonding materials in sufficient amount to impart appreciable color to the stone): brownstone (ferruginous sandstone of dark brown or reddish brown color), arkose, arkosic sandstone, or feldspathic sandstone (a sandstone that contains an abundance of grains of feldspar), conglomerate (a sandstone composed in large part of rounded pebbles, also called puddingstone). The term “brownstone” was applied originally to certain Trassic sandstones of the Connecticut Valley in Massachusetts (Longmeadow sandstone), Connecticut (Portland sandstone), and to similarly appearing reddish-brown sandstone quarried in and near Hummelstown, PA. Thus the term originally had geographic significance, but such geographic limitation is undesirable.
• 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.
• scale – thin lamina or paper-like sheets of rock, often loose, and interrupting an otherwise smooth surface on the stone.
• schist – a loose term applying to foliated metamorphic (recrystallized) rock characterized by thin foliae that are composed predominantly of minerals of thin platy or prosmatic habits and whose long dimensions are oriented in approximately parallel positions along the planes of foliation. Because of this foliated structure, schists split readily along these planes and so possess a pronounced rock cleavage. The more common schists are composed of the micas and other mica-like minerals (such as chlorite) and generally contain subordinate quartz and/or feldspar of comparatively fine-grained texture; all graduations exist between schist and gneiss (coarsely foliated feldspathic rocks).
• scoria – irregular masses of lava resembling clinker of slag; may be cellular (vesticular), dark-colored and heavy.
• scotia – a concave molding.
• sculpture – statuary cut from stone by a sculptor using hand tools and polishing materials.
• sedimentary – rock formed chiefly of quartz, kaolite, calcite and dolomite.
• semi-rubbed – a finish achieved by rubbing (by hand or machine) the rough or high spots off the surface to be used, leaving a certain amount of the natural surface along with the smoothed areas.
• serpentine – a hydrous magnesium silicate material of igneous origin, generally a very dark green color with markings of white, light green or black. One of the hardest varieties of natural building stone.
• setting space – a term used to indicate the distance from the finished face of the marble to the face of the back-up wall.
• shaped stone – cut stone which has been carved, ground or otherwise processed.
• shear – a type of stress; a body is in shear when it is subjected to a pair of equal forces which are opposite in direction and which act along parallel planes.
• shot-sawn – description of a finish obtained by using steel shot in the gang sawing process to produce random markings for a rough surface texture.
• shot-sawn finish – a rough gangsaw finish produced by sawing with chilled steel shots.
• sill – a flat stone used under windows, doors, and other masonry openings.
• siltstone – a fine-grained non-carbonate clastic rock composed of at least 67 per cent of detrital grains of quartz and silicate minerals of silt size. Siltstones are rarely marketed as such but commonly are considered as fine-grained sandstones. This class of sediments is texturally transitional between sandstones and shales (mudstones). Many bluestones and siliceous flagstones fall within this category. The term is included in these definitions chiefly to explain the relationship of some siliceous flagstones to the sandstone category.
• slab – a lengthwise cut of large quarry block of stone approximately 5′ x 8′ in size.
• 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. Essential mineral constituents of slates are usually members of the mica group, commonly sericite, muscovite, and paragonite; of the clay group, chiefly illite and kaolinite; and of the chlorite group. Common accessory minerals are iron oxides, calcite, quarts, and feldspar. Other minerals may be present also as minor accessories. Most slates are derived from shales. Others are derived from fine-grained igneous rock, chiefly volcanic tuffs, but these are rare and of little commercial importance.
• slip sill – a stone sill set between jambs (see lug sill).
• smooth finish – description of the finish produced by planer machines plus the removal of objectionable tool marks. Also known as “smooth planer finish” and “smooth machine finish” snapped edge, quarry cut or broken edge – a natural breaking of a stone either by hand or machine. The break should be at right angles to the top and bottom surfaces.
• soapstone – a massive variety of talc with a soapy or greasy feel used for hearths, washtubs, table tops, carved ornaments, chemical laboratories, etc., known for its stain-proof qualities.
• soffit – the finished, exposed underside of a lintel, arch or portico.
• sound stone – stone which is free of cracks, fissures, or other physical defects.
• spall – a stone fragment that has split or broken off.
• spalls – sizes may vary from chip-size to one and two man stones. Spalls are primarily used for taking up large voids in rough rubble or mosaic patterns.
• spandrel wall – part of a curtain wall above the top of a window in one story and below the sill of the window in the story above.
• splay – a beveled or slanted surface.
• spline – a thin strip of material, such as wood or metal, inserted into the edges of two stone pieces or stone tiles to make a butt joint between them.
• split – division of a rock by cleavage.
• split face (natural bed) – sawn against the grain showing the natural bed – grain of the stone – as it was formed.
• split face (sawed bed) – usually split face is sawed on the beds and is split either by hand or with machine so that the surface face of the stone exhibits the natural quarry texture.
• splitstone finish – obtained by sawing to accurate heights then breaking by machine to required bed widths. (normal bed widths are 3 ½″ (90 mm).
• spot or spotting – an adhesive contact, usually of plaster of paris, applied between the back of marble veneer and the face of the back-up wall to plumb or secure standing marble.
• stacked bond – stone that is cut to one dimension and installed with unbroken vertical and horizontal joints running the entire length and height of the veneered area.
• start – a small fissure.
• statue – a sculpture of a human or animal figure.
• sticking – expression in the marble finishing trade describing the process of cementing together broken slabs/pieces of marble.
• 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.
• stool – a flat stone, generally polished, used as an interior sill.
• stratification – a structure produced by deposition of sediments in beds or layers (strata), laminae, lenses, wedges, and other essentially tabular units.
• strip rubble – generally speaking, strip rubble comes from a ledge quarry, the beds of the stone, while uniformly straight, are of the natural cleft as the stone is removed from the ledge, and then split by machine to approximately 4 inch (100 mm) widths.
• strips – long pieces of stone, usually low height ashlar courses, where length to height ratio is at maximum for the material used.
• styrolite – a longitudinally streaked, columnar structure occurring in some marbles and of the same material as the marble in which it occurs.
• surround – an efframement.

T

• tablet – a small, flat slab or surface of stone, especially one bearing or intended to bear an inscription, carving or the like.
• template – a pattern for repetitive marking or fabricating operation; “safe” a water closet base.
• terrazzo – a type of concrete in which chips or pieces of stone, usually marble, are mixed with cement and are ground to a flat surface, exposing the chips, which take a high polish.
• texture – three dimensional surface enrichment independent of color.
• thermalled – textural enhancement created by flaming the stone surface with intense heat.
• thin stone – stone slabs generally of two inches or less in thickness.
• thin marble – a fabricated marble unit of 2 inches (50 mm) thick.
• tile – a thin modular stone unit.
• tolerance – dimensional allowance made for the inability of men and machines to fabricate a product of exact dimensions.
• throat – the name sometimes given to the small groove under the windowsill or dripstone, intended of deflect rain water from the wall face.
• tooled finished – customarily are four, six or eight parallel, concave grooves to the inch.
• tracery – ornamentation of panels, circular windows, window heads, etc.
• translucence – permitting light to pass through with little diffusing. Certain marble varieties are translucent.
• 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 stalactic 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 stalactic structure. Some that take a polish are sold as marble and may be classified as travertine marble under the class of “Commercial Marble.”
• tread – a flat stone used as the top walking surface on steps.
• trim – stone used as decorative items only, such as sills, coping, enframements, etc., with the facing of another material.
• trimmer arch – a stone arch, usually a low-rise arch, used for supporting a fireplace hearth.
• tuff – cemented volcanic ash, many varieties included.

U

• undercut – cut so as to present an overhanging part.

V

• vein cut – cutting quarried marble or stone perpendicular to the natural bedding plane.
• veinings – colored markings in limestone, marble, alabaster, etc.
• veneer stone – any stone used as a decorative facing material which is not meant to be load-bearing.
• venting – creating an outlet in a wall for air and moisture to pass through. (see cavity vent.)
• verd (or verde) antique – a marble composed chiefly of massive serpentine and capable of being polished. It is commonly crossed by veinlets of other minerals, chiefly carbonates of calcium and magnesium.
• vug – a cavity in rock, sometimes lined or filled with either amorphous or crystalline material, common in calcereous rocks such as marble or limestone.

W

• wall plate – a horizontal member anchored to a masonry wall to which other structural elements may be attached. Also called “head plate.”
• walls – one of the sides of a room or building connection floor and ceiling or foundation and roof:
• wall, bearing – a wall supporting a vertical load in addition to it own weight.
• wall, cavity – a wall in which the inner and outer wythes are separated by an air space but tied together with metal ties.
• wall, composite – a wall in which the facing and backing are of different materials and bonded together with bond stones to exert a common reaction under load.
• wall, veneer, or faced – a wall in which a thin facing and the backing are of different materials but not so bonded as to exert a common reaction under load.
• wall, wind (wined) – a twisting warp from cutting slabs in the gang saws.
• wall, wythe – the inner or outer part of a cavity wall.
• wall tie – a bonder or metal piece which connects wythes of masonry to each other or to other materials.
• wall tie cavity – a rigid, corrosion-resistant metal tie which bonds two wythes of a cavity wall. It is usually steel, 3/16″ in diameter and formed in a “Z” shape or a rectangle.
• warped walls – generally a condition experienced only in flagging or flagstone materials; very common with flagstone materials that are taken from the ground and used in their natural state. To eliminate warping in stones it would be necessary to further finish the material, by methods such as machining, sand rubbing, honing or polishing.
• wash – a sloped area, or the area water will run over.
• water bar – typically a strip in a reglet in window sill and stone below to prevent water passage.
• water table – a projection of lower masonry on the outside of the wall, slightly above the ground. Often a damp course is placed at the level of the water table to prevent upward penetration of ground water.
• waxing – an expression used in the marble finishing trade to indicate the filling of natural voids with color blended materials.
• wear – the removal of material or impairment of surface finishing through friction or impact use.
• weathering – natural alteration by either chemical or mechanical processes due to the action of constituents of the atmosphere, surface waters, soil and other ground waters, or to temperature changes; the inclined top surface of a stone such as a coping, cornice, or window sill.
• wedging – splitting of stone by driving wedges into planes of weakness.
• weep holes – openings placed in mortar joints of facing material at the level of flashing to permit the escape of moisture.
• wind (wined) – a twisting warp from cutting slabs in the gang saws.
• wire saw – method of cutting stone by passing a twisted, multistrand wire over the stone and immersing the wire in a slurry of material.
• wythe – the inner or outer part of a cavity wall.