Stone Dictionary S

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Saddle — a flat strip of stone projecting above the floor between the jambs of the door; a threshold.

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 gangsaw; 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 colours 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 laminac ferruginous sandstone (iron oxide or hydroxide minerals (hematite,, limonite, et al) as interstitial or as boding materials in sufficient amount to impart appreciable colour of stone); brownstone (ferruginous sandstone of dark brown or reddish brown colour), 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 puddingstone). The term “brownstone” was applied originally to certain Trassic sandstone 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, gangsaw 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; characterised as diamond sawn, sand sawn, chat sawn and shot sawn.

Scale — thin lamina or paper-like sheets of rock, often loose and interrupting and otherwise smooth surface on the stone.

Schist — a loose term applying to foliated metamorphic (recrystallized) rock characterised by thin foliae that are composed predominantly of minerals of thin platy or prismatic 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 son 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 (coarse foliated feldspathic rocks).

Scoria — irregular masses of lava resembling clinker of slag; may be cellular (vesticular), dark-coloured and heavy.

Scotia — a concave molding.

Sculpture — the work of a sculptor in three-dimensional form by cutting from a solid block of stone.

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 of igneous origin, generally a very dark green colour 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 sto

ne 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 used steel shot in the gangsawing process to produce random markings for a rough surface texture.

Sill — a flat stone used under windows. Doors, and other masonry openings.

Silstone — a fine-grained non-carbonate clastic rock composed of at least 67% of detrital grains of quartz and silicate minerals of silt size. Silstones 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 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. 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 tight angles to the top and bottom surfaces.

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. 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 — that 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 bevelled or slanted surface.

Spline — a thin strip of material, such as wood or metal, inserted into the edges of two stones pieces or stone tiles to make a butt joint between them.

Split — division of a rock by cleavage.

Split face stone — stone on which the face has been broken to an approximate plane.

Splitstone finish — obtained by sawing to accurate heights then breaking by machine to required bed widths. (Normal bed widths are 3 ½ inches (90 mm).

Spot or spotting — an adhesive contact, usually of plaster or 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 — an expression used in the marble finishing t5ade to describe the process of cementing together of broken slabs or 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 if 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 (100mm) 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 enframement.