Appearance  
The split stone finish gives a very irregular surface that may have quite high relief. Bumps, hollows and pits are randomly developed throughout and thickness may vary along the edges.

Colour    
Dark grey with random paler patches where crinoids are exposed. Calcite crystals may give surface fleck.

Production   
Hydraulic guillotine for most ashlar applications. Larger cladding panels may be split by hand or more commonly produced by selectively trimming the ex-quarry blocks prior to frame sawing.

Application    
The product of guilloting may be used directly for setts and small paviors. (Maximum size 250 mm x 500 mm) Guillotined blocks may be used as ashlar where rustic finishes are required. Some 'touching up' on site will be essential to prevent the sawn sides being visible on the finished structure

Guillotining is commonly used as a rough sizing stage in the production of dressed ashlar. The irregular faces are reworked by a mason to give a consistent pattern.

Larger split stone panels are produced by sawing to size and dressing the edges to give a match between adjacent panels.

Appearance  
Flat parallel even tooling tracks separated by narrow lines of grey split stone. Standard finishes use 150 and 200 lines per metre but other pattern densities are available.

Colour    
Pale blue grey with subtle tone variations depending on the density of the tooling.

Production   
The sawn slab is tooled using multiple disc cutter heads with diamond impregnated segments. The head is mounted perpendicular to the slab and makes sequential parallel passes to produce the pattern. Some cutter heads may produce slightly asymmetrical grooves and in these cases the orientation has to be carefully checked when placing the finished limestone.

Application
Ashlar for sills, steps, lintels, and piers. Monuments and grave kerbs. Internal and external cladding.

Appearance  
The surface of the stone is covered in closely spaced short irregular chisel marks that are usually at an angle of about 45 degrees from the edge. Less commonly, the pattern may be roughly parallel to the edge of the block or at an angle of about 60 degrees from the bed. The cuts are typically between 1 mm and 2 mm in width with a similar spacing. The depth is normally around 1 mm.

Colour    
The overall colour of the stone is pale blue grey with the contrast between the chisel marks and the rough stone only apparent at close range.

Production   
The patterning was originally associated with fining down of an ashlar surface before a ground or honed finish was applied. It was originally produced using a sharp fine pointed chisel in a pneumatic hammer but is now almost exclusively produced by machine using a multiple-ridged chisel head. Fine punched finishes may resemble mechanical old cut.

Application
The mechanical old cut finish is widely used on floor tiles, setts, paviors and kerbs where it produces a good non-slip surface. It is also used widely on sills, lintels, mouldings and general ashlar as well as grave stones and kerbs. The relatively smooth surface also makes this dressing suitable for both internal and external cladding.

Appearance  
Dense surface pattern of irregularly spaced circular impact points between 1 mm and 3 mm in width and depth. The darker rough limestone surface may be exposed to a variable extent depending on the force employed behind the hammer head and the density of patterning. An unworked margin must be left to prevent edge damage during processing. This is occasionally delineated by a chiselled line and becomes part of the overall surface finish when cladding or ashlars are dressed individually.

Colour    
Pale, grey-blue with whitish flecks.

Production   
Originally a manual dressing produced by repeatedly impacting a sawn surface with a hammer face that had a checkboard pattern of pyramidal points (Bouchard). Pattern variation can be produced by changing the points on the head. The hand worked hammer dressing often had an underlying rectangular or circular pattern.   

The finish is now almost entirely produced by the use of a random orbiting pneumatic hammer head that generally gives a denser surface cover of impact points. The impact force and the point density on the head can be controlled to produce variations in the finished pattern.   

The mechanical dressing can only be applied to flat surfaces, but a hand held pneumatic hammer equipped with a bouchard head can be used to match curved surfaces. Sawn slabs are often hammer dressed then cut to size to give a uniform finish to cladding.

Application
Hammer dressing gives a relatively smooth surface that makes the dressing suitable for both interior and exterior cladding. It is often applied to paviors and floor tiling to produce a non-slip surface. It may also be applied to stair nosings to give anti-slip strips on sawn, ground, honed or polished finishes. The finish can be applied to all sawn ashlars.

Appearance  
Flat, even surface with fine circular scoring that may be difficult to identify in some finishes. The calcite grain structure and fossil debris will be apparent on the face of the limestone.

Colour    
Pale, grey-blue on the coarser grit finishes but becoming increasingly darker where finer grits are used in processing. Crinoids will develop a stronger paler contrast to the matrix as the finish becomes finer.

Production   
Large slabs are finished using an oscillating rotating head equipped with grinding pads. Various grades of grit are available giving smoother and darker finishes. The processed slabs are cut to size for cladding and some ashlar applications. Smaller or irregular shapes can be processed using hand-held power drives with flat or profiled heads.

Application
Internal and external cladding and ashlar. Sills, steps, lintels, cappings, grave stones and kerbs. May also be used for internal and exterior floor tiles.

Appearance  
Even matt surface with no tooling marks.

Colour    
Dark, blue-grey but may exhibit subtle tone variations depending on the area of the quarry from which the stone was extracted. Fossil debris, particularly crinoids, form a contrasting paler mottling on the surface. Most quarries have certain beds that, when honed, give a black colour. Certain 'shell' beds give a black matrix with strongly contrasting white bivalves.

Production   
Honed finishes are applied to large slabs using a rotating head equipped with fine grinding pads. The head moves around the slab in a random pattern and a continuous supply of water to the surface gives a very fine, smooth, matt finish. Finished slabs are cut to size for cladding and some ashlar. Irregular or small surfaces may be honed using hand-held equipment with flat or profiled fine grinding heads.

Application
Apart from some monumental and sculpture applications, honed finishes are not used for external applications as acid rain, which is now endemic in industrialized countries, will cause surface degradation. The finish is suitable for internal cladding, steps, sills, skirtings and floor tiles. It may also be used in furniture, pedestals, tops for vanity units and counters.

Appearance  
Regular flaked surface with small bumps and hollows to a depth of approximately 2mm

Colour    
Light to dark grey mottled effect.  Certain shell beds give a grey matrix with consisting white fossils.

Production   
Flamed finishes are applied with a combination of a high temperature naked flame and water.  The heating and cooling action flakes the surface of the slab to a depth of approximately 2mm. The finish can only be applied to a flat surface by machine finish.

Application
Internal and external cladding, setts, paviors and floor tiles for internal and external applications

Appearance  
Smooth, glossy, highly reflective surface where the fossil traces may be clearly seen. The abundant large calcite grains often give an apparent depth to this finish in the Irish Blue Limestone. The sharp contrast between white bivalve shells and the dark matrix in the 'shell' beds; and the patterning resulting from the different ways the shell may be cut, can make those beds particularly attractive for polished finishes.

Colour    
Dark, blue-grey to black depending on the bed being processed. Fossil traces, white spots, calcite veining and stylolites will all show up clearly on the surface.

Production   
Polished finishes are applied to large slabs using a rotating head equipped with soft slightly abrasive pads. A continuous supply of water washing across the surface and random oscillation of the head gives the deep lustrous finish. The slabs are cut to size for cladding and some ashlar. Irregular or small surfaces may be polished by hand.

Application
Polished finishes are unsuitable for external applications. Polished limestone can be used for internal cladding, steps, sills, skirtings and floor tiles. It may also be used in furniture, pedestals, tops for vanity units and counters although there may be a risk of scoring in these application.