Natural Stone Definitions
P
Palletize
To stack and secure stone units to a pallet for ease, safety, and efficiency in handling and transport.
Panel
A term used to describe either a single unit of fabricated stone veneer, or a pre-assembled panel including multiple stone units affixed to a structural panel framework.
Parapet
A low wall along the edge of a terrace, roof, or balcony, which is usually simply the extension of the exterior wall below it.
Parge
Patina
The change in color or texture of the surface of natural stone due to age or exposure to various elements.
Paver
A single unit of fabricated stone for use as an exterior paving material.
Paving Stone
Stone used as an exterior wearing surface, as in patios, walkways, driveways, etc.
Pedestal
In classical architecture, the support for a column or statue, consisting of a base, dado, and cap.
Pediment
The gable end of a roof in classical architecture. Located above a horizontal cornice member, it comprises the raking cornices and the tympanum. It is typically triangular, but can also be curved when applied as a decorative element over windows.
PEL
Permissible Exposure Limit: PELs are established and enforced by OSHA to protect workers against the health effects of overexposure to hazardous substances.
Percussion Drilling
Any method of drilling that includes a combination of hammering blows along the longitudinal axis of the bit with rotation of the bit. Also called “hammer” drilling.
Perforated Wall
One which contains a considerable number of relatively small openings, often called pierced wall or screen wall.
Pergola
Garden structure formed by two rows of posts or pillars with joists and open framing above, often covered by climbing plants and shading a walkway.
Phenocryst
One of the relatively large and ordinarily conspicuous crystals of the earliest generation in a porphyritic igneous rock.
Pilaster
A shallow, engaged pier or column projecting from a wall, only decorative in function.
Pillowed Finish
A pillowed finish is created when a chisel is used to remove material around the edges of a square or rectangular piece of stone. When installed, stone with a pillowed finish looks natural, as if each square or rectangle is protruding out from the installed surface. Surface roughness can vary from rough (1/4-2″) to very rough (>2”), depending on the process. Other patterns produced by chiseling include rockfaced, pineapple and point stalk. While fabrication can be machine-aided, hand-made versions are generally considered to be more attractive.
Pineapple Finish
A pineapple finish is achieved when chisel indentations are made in the surface of the stone, leaving a pockmarked, rough surface that mimics the skin of a pineapple. Pineapple patterns can be random or geometric. The overall look is artistic. Surface roughness can vary from somewhat rough (1/16-1/4”) to very rough (>2”), depending on the process. Other patterns produced by chiseling include rockfaced, pillowed and point stalk. While chiseling can be done by machines, hand-chiseled finishes are generally considered to be more attractive.
Pit Quarry
Below ground-level quarry.
Pitch Faced Finish
A rustic finish for veneer stone created with a split or chiseled face, and dressed along the stone’s perimeter to produce convex projection. See also Rockfaced Finish.
Pitched Stone
See Pitch Faced Finish.
Plinth
- The base block at the junction of the stone base and trim around a door or other opening.
- The bottom stone block of a column or pedestal.
Plucked Finish
A stone surface produced by setting a planer blade so deep that it removes stone by spalling rather than by shaving.
Plutonic
Applies to igneous rocks formed beneath the surface of the earth, typically with large crystals owing to the slowness of cooling.
Pointing
The final filling and finishing of mortar joints that have been raked.
Point Stalk Finish
A point stalk finish is created when grooves are chiseled to run in a linear direction. Surface roughness can vary from somewhat rough (1/16-1/4”) to very rough (>2”), depending on the process. Other chiseled patterns include rockfaced, pillowed and pineapple. Grooved is a similar finish that is obtained by carving rather than chiseling. While fabrication can be machine-aided, hand-made versions are generally considered more attractive.
Polished Finish
Stones are polished by the repeated application of abrasive treatments. The polishing is done by machine. This technique produces a shiny surface, with almost zero porosity, therefore improving wear resistance. Polished finishes highlight the color and markings of natural stone. Polished surfaces are commonly used in interior and exterior wall cladding, fireplace surrounds, and countertops. This finish is not recommended for high-traffic areas since polishing reduces slip and scratch resistance. Surface roughness is always slick (< 1/64”). A honed finish can create a less or non-reflective look similar to polished.
Polishing
A process utilizing abrasives in combination with specific polishing powders and/or chemicals to produce a glossy, highly reflective surface finish on the stone.
Polishing Compounds
Any of the powders or chemicals used in addition to the abrasive machine heads that are used to achieve a polished finish.
Polishing Cream
A polishing compound that is supplied in a cream or paste consistency.
Polishing Pads
Small diameter flexible disks with embedded abrasives used with handheld tools or small portable machines for polishing of stone. These pads may be used in combination with compounds and may be used either wet or dry.
Porphyry
An igneous rock characterized by distinct and contrasting sizes of coarse and fine-grained crystals. Used as a decorative building and/or paving stone.
Portico
A porch formed by a roof supported with columns, similar to a temple front.
Poultice
Any absorbent material (powder, cloth, etc.) used in a saturated condition with water or solvent-based fluids and applied to a stone surface for the purpose of removing embedded stains.
PPE
The abbreviation for Personal Protective Equipment, such as protective clothing, safety toe shoes, helmets, goggles, etc., designed to protect the wearer’s body from injury from exposures in the work environment.
Preassembled Units
A composite unit consisting of a structural backing, usually steel or concrete, multiple panels of stone, and necessary anchorage and connection hardware that is built off-site and transported to the construction site for erection.
Precast
In stone facades, it refers to a bi-material panel consisting of multiple stone face units and a concrete backer panel. The panel is cast off-site, then transported to the construction site for erection.
Pressure Relieving Joint
Primer
- A unit or package of ignition devices used to initiate other explosives or blasting agents in the quarry.
- A liquid coat applied to increase bond strength of a joint sealant.
Privacy Partition
Producer
Company or person that quarries and supplies dimensional stone to the commercial market.
Profile Wheel
Any grinding wheel that has convex or concave shapes and can be adapted to a router, handheld grinder, or CNC machine for the purpose of producing the desired shape to a stone edge.
Projections
Any stone that is installed in a position outward of the balance of the wall for aesthetic or water control purposes.
Prospecting
The practice of locating mineral deposits of commercial value.
Pumice
Exceptionally cellular, glassy lava resembling a solid froth.
