Glossary of Stone-Related Terms

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CALCARENITE: Limestone composed predominantly of clastic sand-size grains of calcite, or rarely aragonic, usually as fragments of shells or fossils. Some calcarenites contain oolites and may be termed oolitic limestone. Calareous quart-based stone in which the calcium carbonate is present chiefly as binding material are not included in this category.

CALCAREOUS: Calcium-bearing rock.

CALCITE: The natural mineral form of calcium carbonate.

CALCITE LIMESTONE: A limestone containing not more than 5% of magnesium carbonate.

CALCITE MARBLE: A crystalline variety of limestone containing not more than 5% of magnesium carbonate.

CALCITE STREAKS: Descriptions 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.

CALCIUM OXIDE: Calcined limestone.

CAMBER: A slight rising from the horizontal, to gain an actual or apparent effect of arching.

CANOPY: A sheltering roof over a niche or a doorway.

CANTERA: A volcanic quartz-based stone with qualities similar to Adoquin, but not as dense; quarried in Mexico.

CANTILEVER: A structural member, supported at only one end, that projects from a wall.

CAP: Masonry units laid on top of a finished wall, column, door, or molding.

CAPACITY INSULATION: The ability of masonry to store heat as a result of its mass, density and specific heat.

CAPILLARY ACTION: The movement of a liquid in the interstices of a porous material, as a result of surface tension; the phenomenon responsible for dry materials sucking moisture above the normal water level.

CAPITAL: Column cap, the top member or group of members of a column, pier, shaft, or pilaster.

CAPPING: See coping ..

CAPSTONE: The crowning stone of a structure; differing from capital in that it is not a supporting member.

CARBONATE: A salt of carbonic acid.

CARBONIC ACID: A weak acid.

CARVE: Shaping by cutting a design to form; the trade of a sculptor.

CARVER: In the stone industry, the artisan who does carved work.

CARVING: Cutting of ornamental shapes, figures, etc… from models or details, which are too intricate to produce from patterns.

CAST STONE: A precast concrete building stone manufactured to simulate dimension stone.

CATALYST: A substance which accelerates a chemical reaction but appears to remain unchanged itself (i.e. a hardener that accelerates the cure of synthetic resin adhesive).

CAULK: A non-staining, non-hardening putty-like mastic, usually applied to stone joints with a pressure gun.

CAULKING: The application of a sealant in a joint or opening to prevent the passage of water, air, dust, and noise. Or, making a joint tight or leak proof by sealing with an elastic adhesive compound.

CAVITY VENT: An opening in joints of veneer to allow the passage of air and moisture from the wall cavity to the exterior.

CAVITY WALL: An exterior wall, usually of masonry, consisting of an outer and inner wythe separated by continuous airspace.

C/B RATIO: The ratio of the weight of water absorbed by a masonry unit when immersed 24 hours in cold water to the weight of water absorbed after an additional immersion for five hours in boiling water. Also called the saturation coefficient.

CELL: Cells are distinguished from core holes by being larger in size.

CEMENT: A hydraulic mixture, without aggregate, consisting of a calcined mixture of clay and pulverized limestone.

CEMENT PUTTY/CREAM/BUTTER: A thick, creamy mixture made with pore cement and water which is used to strengthen the bond between the stone and the setting bed.

CEMENTITIOUS: Made from, or composed of, portland cement.

CENTERING: Temporary formwork for the support of masonry arches or lintels during construction. Also called center (s).

CHAMFER: To bevel the junction of an exterior angle. Or, to cut away the edge where two surfaces meet in an external angle, leaving a bevel at the junction.

CHANCEL: That part of a church interior reserved for clergy and containing the alter.

CHASE: A continuous recess in a wall to receive pipes, ducts, conduit, etc….

CHAT SAWED: Description of a textured stone finish, obtained by using chat sand in the gang sawing process.

CHAT SAWN FINISH: A rough gang saw finish produced by sawing with course chat.

CHECK: A rebate, normally larger than a fillet.

CHECKER WORK: Masonry of square-face stones not breaking joints.

CHIMNEY: A shaft, approximately vertical, which helps create a draft for conducting the smoke and gases of combustion from above a fire to the outside.

CHIMNEY BREAST: The exterior face of the wall directly above the fireplace opening.

CHIMNEY LINING: Fire clay, terra cotta, or refractory cement built inside a chimney.

CHIMNEY THROAT: That part of a chimney directly above the firebox where the walls are brought close together.

CHIP: A small, irregularly shaped stone piece dislodged, usually from the edge, from a stone piece.

CIRCULAR CIRCULAR FACE: A stone face worked to convex spherical shape.

CIRCULAR CIRCULAR SUNK FACE: A stone face worked to concave spherical shape.

CIRCUALAR SAW: Machine with power-driven revolving steel disc, rimmed with diamond or other abrasive elements.

CIRCUALAR FACE: A stone face worked to convex circular (not spherical) shape.

CIRCULAR SUNK FACE: A stone face worked to a concave circular (not spherical) shape.

CLADDING: An exterior veneer stone covering that is non-load bearing.

CLASTIC: Stone fragments that are derived from pre-existing rocks or minerals.

CLASS OF UNIT: A ranking of masonry units according to their different grades or types in ASTM specifications, the different raw materials they are manufactured from, or other characteristics.

CLAW TOOL: Toothed chisel used in roughing out process.

CLAY: A natural mineral aggregate consisting essentially of hydrous aluminum silicate. It is plastic when sufficiently wetted, stiff when dried, and vitrified when fired to a sufficiently high temperature.

CLAY MORTAR: A soft, low lime mortar usually used when lime was expensive and difficult to procure. Its primary usage was in remote areas for small scale buildings.

CLEAN BACK: The visible end of a stone laid as a bond stone.

CLEANING: The removal of marks, dust, and other extraneous materials from the surface of the stone.

CLEANOUT HOLES: Openings at the bottom of a grout space for cleaning mortar droppings and other debris prior to grout placement.

CLEAR COATING: An invisible to glossy film or penetrate applied to substrates to protect, repel or resist water and hydration of minerals.

CLEARANCE: Space allowed to facilitate erection of units and provide for thermal and other estimated movements in structure.

CLEAVAGE: The ability of a rock mass to break along natural surfaces; a surface of natural parting. Also used to refer to the plane or planes along which a stone may likely break or delaminate.

CLEAVAGE MEMBRANE: Membrane that provides a separation and slip sheet between the mortar setting bed and the backing or base surface.

CLEAVAGE PLANE: Plane or planes along which a stone may likely break or delaminate.

CLOSER: The last masonry unit or portion of a unit laid in a course.

CLOSURE: Supplementary or short length units used at corners or jambs to maintain bond patterns.

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 altering the appearance of the stone.

COBBLESTONE: A natural rounded stone large enough for use in paving.

CODE: Legal restrictions of a given locality governing the building of various types of structures.

COLLAR JOINT: The vertical longitudinal joint between wythes of masonry filled with mortar or grout.

COLUMN: An isolated vertical member whose horizontal dimension measured at right angles to the thickness does not exceed three times its thickness and whose height is at least three times its thickness.

COMMERCIAL MARBLE: A crystalline rock composed predominately of one or more of the following minerals: 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 concealed material.

COMPOSITE ACTION: Transfer of stress between components of a member designed so that in resisting loads, the combined components act together as a single member.

COMPOSITE MASONRY: Multi-component masonry members acting with composite action.

CONCRETE: A composition material consisting of Portland Cement, aggregate, and water. When mixed together, will result in a chemical action that will set and harden into rock-like mass.

CONCRETE MASONRY UNIT: A masonry unit made of Portland Cement, water, and mineral aggregates, formed into a rectangular prism.

CONDENSATION: Dampness of interior surfaces caused by the release of water as it cools below the dew point; the formation of frost or water when air carrying water vapor comes in contact with a cold surface, cooling the air and reducing its ability to hold moisture.

CONGLOMERATE: A stone similar to sandstone but the rock particles are rounded or angular gravel rather than sand; an aggregate of rounded and water-worn pebbles and boulders cemented together into a coherent stone.

CONSOLIDATION: Treatment of the stone surface with a liquid solution which is commonly brush or spray applied; various stone consolidation processes can extend the life of stone and retard the decay process, but they cannot permanently arrest deterioration. Consolidation techniques employ both organic and inorganic chemicals. Inorganic processes have long-life and exhibit similar expansion-contraction behavior as treated material. Most inorganic processes cannot reattach loose pieces of stone or fill gaps in large cracks; adhesives may be required for the purposes. Organic processes are based on the use of synthetic resins. Their life span is generally less than that of inorganic material, but they can be especially effective with porous stone as well as comprehensive strengths. Epoxy resins, for example, are good adhesives and weatherizers, but current available epoxies are sensitive to ultraviolet rays which tend to discolor in time and do not weather well. Mixtures and combinations of both organic and inorganic treatments such as ethyl silicate are continually being developed to take advantage of the benefits of both treatments.

CONTAINER: An enclosed truck body that is usually used to hold and carry imported dimension stone into the United States.

CONTOUR SCALING: A crust forming across the surface of sandstones and limestones which follows the contour of the surface rather than the bedding planes of the stones; the result of direct pollution; the pores of the stone are blocked by formations of recrystallized calcium sulfates.

CONTRACTION JOINTS: Spaces where panels are joined and which expand as the panels contract.

CONTRACTOR: One who erects and installs fabricated dimensional stone.

CONTROL JOINT: Provision for the dimensional change of different parts of a structure due to shrinkage, expansion, temperature variation or other causes, so as to avoid the development of high stresses.

COPE STONE: The horizontal top stone of a wall or similar stone construction , usually flat.

COPING: A cap or covering course on top of masonry wall. Designed to shed water, protect the top and provide a finished, closed appearance to the wall. Commonly extended beyond the wall face and incorporating a drip. SEC: Single edge coping; DEC: Double edge coping.

COQUINA: Limestone composed predominately of shells or fragments of shells loosely cemented by calcite. Coquina is course-textured and has a high porosity. The term is applied principally to a very porous rock quarried in Florida.

CORAL LIMESTONE: A limestone consisting of the calcareous skeletons of corals, often containing fragments of other organisms and usually cemented by calcium carbonate.

CORBEL: Projecting successive courses of masonry out from the face of the wall to increase the wall thickness or to form a shelf or ledge.

CORBEL PLATES: Concealed plates of nonferrous metal fixed into a structure to support stone cladding at intervals and over openings.

CORE: Continuous openings or perforations within extruded clay products.

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.

CORNICE: A molded projecting stone at the top of an entablature or facade.

CORROSION RESISTANT: Steel items which have been treated or coated to retard harmful oxidation or other corrosive action.

COUNTERSINK: An added depression below a surface, as to receive the head of a nail, screw, or bolt; also, the sinkage of a small area below the surface plane.

COURSE: A continuous horizontal band of stone of constant height.

COURSED VENEER: This is achieved by using stones of the same or approximately the same heights. Horizontal joints runs on the entire length of the veneered area. Vertical joints are constantly broken so that no two joints will be over one another.

COUSSINET: French for the stone at the top of a pier supporting the lowest stone of an arch.

COVE BASE: A concave stone molding.

COVE JOINT: A concave joint shaped with a tool.

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, through the grain, matrix, or vein.

CRAMP: A ‘U’ shaped metal anchor for holding two adjacent units of stone together.

CRANDALL: A multi-pointed hammer for dressing the face of stone.

CRATE: A wooden protective case in which stone is packed for shipment.

CRATERING: Depression in a coating film usually caused by air or solvent trapped in the coating, forming bubbles which break after the film has set sufficiently to prevent leveling.

CRAZING, CRAZE, CRACK: Fine, random cracks or fissures in a network on or under a surface of plaster, cement, mortar, concrete, ceramic coating or paint film; caused by shrinkage.

CREEP: The permanent and continuing dimensional deformation of material under a sustained load, following the initial spontaneous plastic deformation. In structures particularly concrete, the permanent deflection of structural framing or structural decking resulting from plastic flow under continued stress. In roofing, the permanent elongation or shrinkage of roofing membrane, resulting from thermal or moisture changes.

CROSS-BEDDING: The arrangements of laminations of strata transverse or oblique to the main planes of stratification.

CROSSETTE: ( Croissette, Crosset) A side lug at the upper side of an arch stone, entering a corresponding space on the adjoining stone.

CROWFOOT VEIN: ( Stylolite) Description of a dark gray to black zigzag marking occurring in stone; usually structurally sound.

CROSS-SECTIONAL AREA: The area of a particular portion of a member or the area of a masonry unit.

Gross cross-sectional area: The area delineated by the out-to-out dimensions ofmasonry or a masonry unit in the plane under construction.

Net cross-sectional area: The net cross-sectional area of a masonry unit is the gross cross-sectional area minus the area of the cores or cells. For brickunits cored less than 25% the net area is equal to the gross area. Or, the area of masonry units, grout, and mortar crossed by the plane under consideration based on out-to-out dimensions.

CRYSTALLINE LIMESTONE: Limestone, either calcite or dolomite, composed of interlocking crystalline grains of the constituent minerals and of phaneritic texture. Commonly used synonymous 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.)

CUBIC LIMESTONE: Dimension units more than two inches thick.

CUBIC MARBLE: Fabricated dimensional marble units more than two inches in thickness.

CULL: Material rejected as below the desired or stated grade of stone.

CULTURED MARBLE: An artificial, manmade product, created by mixing minimal amounts of marble dust into a resin.

CURBING: Slabs and blocks of stone bordering streets, walks, etc, producing the change in level between sidewalk and street.

CURE: Formation of a final, more stable, usable state following a chemical or physical reaction induced by heat, radiation, etc… or through evaporation of a solvent.

CURING: The drying and hardening process of mortar after installation. Some materials require damp curing.

CURSTABLE: A course of stones bearing moldings, to produce a string course.

CURTAIN WALL: A lightweight exterior wall system supporting no more than its own weight, the roof and floors being carried by an independent structural framework. Sometimes used in reference to early 19th century brick buildings but more commonly to mid 20th century metal panel and glass exteriors.

CUSHION: A resilient pad to absorb or counteract severe stresses between adjoining stone units and or other materials.

CUT STONE: Finished, dimensional stone, ready to set in place.

CUTTING: Handwork required to finish a stone which cannot be done by machine.

CUTTING STOCK: A term used to describe varying size, finish, and thickness which are used in fabricating treads, risers, copings, borders, sills, stools, hearths, mantels and other special purpose stones.

CUTTING TICKETS: Detailed list for each piece of dimension stone showing exact dimensions including thickness, face finish, edge treatments, carving, molding, hole drilling, and any other fabrication details. These are usually prepared in the drafting department for use in the fabrication plant or shop. Also called shop lists.