Glossary of terms relating to building stones of Edinburgh

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From: Appendix 1 Glossary. McMillan, A.A., Gillanders, R.J. and Fairhurst, J.A. 1999 Building stones of Edinburgh. 2nd edition. Edinburgh: Edinburgh Geological Society.

Agglomerate: rock produced by explosive volcanic activity - coarse angular blocks in a fine-grained matrix.

Andesite: fine-grained, volcanic rock consisting of feldspar and iron-magnesian silicate minerals.

Anhydrite: mineral composed of calcium sulphate (see also gypsum).

Anticline: strata folded in the form of an arch.

Architrave: the lowest horizontal member lying above a column in a colonnaded building.

Ashlar: hewn blocks of masonry finely dressed to size and laid in courses.

Baillie: magistrate in Scottish local government

Barrack: accommodation for itinerant workers, sometimes temporary.

Basalt: black, fine-grained, basic igneous rock, commonly forming lava flows and consisting of iron oxide and silicate minerals including feldspar and pyroxene.

Bedding: natural layers formed during deposition of sediments.

Blaes: old mining term for mudstone or shale, not containing much bituminous material.

Boaster: broad-faced chisel used for dressing stones.

Braided: interwoven stream or river channels, constantly shifting through islands composed of sands, silts and clays.

Broached: Scottish term for work on stone face with pointed tool to produce vertical or horizontal furrows.

Calcite: calcium carbonate, a common constituent of limestone.

Camstone: fine-grained, calcareous stone used for whitening doorsteps.

Cementstone: fine-grained, muddy limestone.

Cladding: thin slabs of stone used as external, non-load-bearing covering to building structure.

Column: free-standing vertical member, normally circular in plan, often conforming to the classical orders.

Conglomerate: sedimentary rock consisting of water-worn pebbles bound together in a sandy matrix.

Corbel: stone or series of stones projecting from a wall used for support.

Cornstone: concretionary limestone formed under arid conditions.

Corinthian: the most ornate of the variations on post and lintel structure found in classical architecture.

Course: continuous layer of stones of uniform height.

Coursed rubble: roughly squared stones in courses to correspond with quoin and jamb stones.

Cross-bedding: in sands a series of inclined bedding planes having a relationship to the direction of current flow (also current-bedding).

Cyclothem: repeated unit in cyclic sedimentation.

Desiccation: the process of drying up.

Dimensioned stone: ashlar or stone prepared to specified dimensions.

Dip: inclination of strata to the horizontal.

Dolerite: black, medium-grained basic igneous rock consisting of iron oxide and silicate minerals including feldspar and pyroxene.

Draft: smooth strip worked on stone face to width of draft chisel.

Dressed: applied to stone with any kind of worked finish.

Droved: tooled with a broad chisel.

Dune-bedding: large-scale cross-bedding typical of sands deposited in desert and beach dunes.

Dyke: sheet-like body of igneous rock which cuts across the bedding of the sedimentary rocks (see also sill).

Efflorescence: development of crystallisation of salts on wall surfaces.

Evaporite: deposit of precipitated salt (e.g. anhydrite, gypsum), evaporation having caused the necessary concentration.

Fault: fracture in rock along which there has been an observable amount of displacement.

Feaks (Fakes): old mining term for thinly bedded shaly, micaceous sandstone or sandy shale (see also flagstone). Feldspar: important group of rock-forming silicate minerals including silicates of sodium,

potassium and calcium.

Felsite: fine-grained igneous rock consisting of feldspar and quartz.

Flagstone: fissile, micaceous laminated sandstone, suitable for roofs and pavements.

Freestone: see Liver Rock.

Gabbro: coarse-grained igneous rock consisting of feldspar and magnesium- and iron-rich silicate minerals including pyroxene and sometimes olivine.

Gin: machine used in hoisting often driven by horses.

Graben: block of the earth's crust down-thrown between two faults.

Granite: coarse-grained igneous rock consisting of quartz, feldspar and very commonly mica.

Greywacke: fine- to coarse-grained, hard sandstone consisting of mainly angular quartz and rock fragments (also known as wacke).

Gypsum: soft white mineral composed of hydrated calcium sulphate.

Indenting: Scottish term for cutting out worn or damaged stone and inserting new (indents).

Ionic: simpler variation of the post and lintel structure found in classical architecture (see also Corinthian).

Jamb: stones forming the vertical surfaces at the sides of doors or windows.

Joint: fracture in the rock with no displacement. Joints often occur in two sets, more or less vertical and at right angles to each other.

Jumper: hand tool for sinking holes in stone.

Limonite: hydrated iron oxide and hydroxide.

Lithology: character of rock in terms of composition, structure and grain size.

Liver rock: massive sandstone without discernible bedding which can be worked in all directions (also freestone).

Mash: Scottish term for Mason's steel hammer weighing 1-2kg.

Metamorphic rock: recrystallized rock derived from pre-existing rocks by action of high temperature and/or pressure in the earth's crust.

Mica: flaky complex hydrated silicate mineral.

Newel: upright column around which the steps of a spiral staircase wind.

Ostracod: minute creature which has jointed limbs and lives inside a bivalve shell.

Pilaster: shallow pier or part column projecting from a wall.

Pillar: free-standing vertical block of stone: circular or polygonal in plan.

Pillar and Stall: method of mining which involved leaving pillars of the material being mined to support the roof (also known as stoop and room).

Pitched: surfaces resembling natural rock produced by pitching tool.

Plat: platform, doorstep or landing.

Plug and Feathers: steel wedge (plug) with half-round steel strip (feathers) on either side, used for splitting stone.

Polished: stone surface worked to a very smooth finish by rubbing.

Pyroxene: group of iron and magnesium (ferro-magnesian) silicate minerals.

Quartz: common rock-forming, hard glassy mineral, silica.

Quoin: stone at external angle of wall.

Random rubble: walling of irregular unsquared stones.

Redd: quarry rubbish.

Rubble (ruble): rough uncut stones of irregular shape and size.

Rusticated joints: where margins of stones are sunk below the general face.

Sandstone: sedimentary rock composed of sand grains naturally cemented.

Scaling: stone flaking-off in thin layers.

Scleroscope: small diamond-tipped rebound hammer used for measuring hardness of a material.

Seatearth: rock composed of clay-, silt- or sand-grade material full of fossilised plant roots, representing a former soil.

Sett: stone roughly squared for paving (also calsay stones).

Sill: sheet of igneous rock intruded along the bedding planes of earlier rocks.

Sneck: small stone in squared rubble work to make up bed bonding.

Squared rubble: walling of irregular squared stones laid in courses.

Stratigraphy: study of stratified rocks including their sequence in time and the correlation of sedimentary sequences in different localities.

Stugged: pecked stone faced with a pick or pointed tool.

Syenite: coarse-grained igneous rock consisting mainly of potassium-rich feldspar and hornblende.

Till: stiff to hard clay with stones, deposited by ice (also boulder clay).

Tirr: material removed as overburden.

Tooled: dressed.

Tuff: consolidated volcanic ash.