Limestones:  Limestones have been extensively used in the past for building purposes. Many of Britain's most famous buildings are built of limestones of various types e.g.; the Houses of Parliament (Anston Stone) most of our great cathedrals - St. Pauls (Portland Stone), Llandaff (Dundry and Lias stones), Wells (Doulting Stone), York Minster (Magnesian Limestone from Tadcaster and Huddleston quarries) etc. The softer nature of limestone was particularly important where elaborate decorative carving of the stone was required. As with the sandstone industry in earlier times, most limestone outcrops were worked, if only locally, for building purposes. In a few areas the production of limestone for building stone developed into a major industry and their products were exported throughout Britain and in some cases abroad e.g Bath and Portland stones. Occupying an important niche in some areas, was the quarrying of relatively soft Chalk (e.g Totternhoe and Clunch) lithologies, for elaborately carved decorative work as in the cathedrals of Ely and Exeter.

Portland stone St Paul's Cathedral, London

Igneous stones 'granites': Throughout the 19th and early 20th centuries Britain was the worlds leading granite producer. The industry was centred, principally in two areas, the north-east of Scotland, notably around Aberdeen and Peterhead, but also at many smaller granitic outcrops (Anderson 1939), and in south-west England around the large but separate igneous intrusive centres in Devon and Cornwall (Harris 1888). Smaller production centres developed at Shap, Cumbria and at Mountsorrel (granodiorite) in Leicestershire. In more recent times there has been a major contraction of our granite industry. Surviving production is still concentrated in these traditional areas but the number of quarries has been significantly reduced. This is despite the fact that in our new buildings ’granite’ still commonly used in considerable amounts for cladding, however, most of it now comes from overseas sources.

Higher Shilstone granite Dartmoor Devon

Elsewhere in Scotland other granite quarries include the deep red Ross of Mull, perhaps best be seen outside Scotland in the ostentatious Albert Memorial in London (Robinson 1987), and grey Criffel/Dalbeattie granite from Kircubright. Output from the Scottish quarries increased from about 12,000 tons in 1797 to 260,000 tons by 1939 (Anderson 1961). 

Granite was produced from several quarries in each of the five separate granite bosses that intrude the Devon and Cornwall peninsular. Production, in its heyday in the 19th century, was centred on the Dartmoor (Hay tor), Bodmin (Cheesewring and De Lank), St Austell (Luxullian), Penryn (Camsew & Penryn) and Penzance areas. In general they can be distinguished from those varieties quarried in Scotland by their coarse often porphyritic nature and the common flow orientation of the feldspars. Though both grey and pink feldspar varieties occur the former tend to dominate. Proximity to the rivers or coast for shipment were again a contributing factor to the national success of the industry in this area.

In most of the rock formations of Britain if the stone was hard enough it was invariably used for local building purposes in the past. Many finer grained, intrusive igneous rocks were used in this way such as the dolerite of the Whin Sill in Northumberland. This hard, fine-grained dark coloured rock or whinstone was used in local village houses (e.g. Craster) but because of its intractable nature was more widely exploited as an aggregate. In Exeter and south Devon the local vesicular basalts known as trap were widely used in its ancient buildings including parts of the original fabric of the cathedral.

Included by geologists in the igneous rock classification are the serpentinites. These colourful ultrabasic igneous rocks are commonly used for the decorative cladding of shop fronts. Most serpentinites are, however, now imported. Two areas of Britain were known for their production of serpentine, the Lizard area of Cornwall and the Isle of Anglesey in Wales. In Anglesey the serpentine was known as the Mona Marble.

Welsh slate roof Llanelian Anglesey

This definition of slate excludes the stone products known as 'stone' slates which are naturally fissile limestones and sandstones, widely used for roofing purposes, but which are not metamorphosed in any way.

Like the granite industry, Britain's slate industry, which dominated world production in the late 19th and early 20th centuries, has suffered not only from foreign competition but also from an increasing tendency to replace natural slate roofing with man-made clay and concrete tiles.

Britain's slate production is still concentrated in its the traditional areas of North Wales, the Lake District and Devon and Cornwall. However, the industry once also thrived in Scotland (Easdale (Tucker 1976), Ballachullish (Fairweather 1974), Foudland (Richey & Anderson 1945?), West Wales (Ri chards 1997) and Leicestershire (Swithland) but has now virtually died out in these areas. This decline cannot be attributed in any way to the quality of the slates produced or to a lack of reserves but probably to economics, and the decline in skilled slaters able to lay slates efficiently in the traditional way. There is also an apparent indifference which architects and planners now seem to have over specifying British slates for new build projects, rarely do you see natural slates used in modern housing developments despite their proven durability.

Britain's 'marble' industry was based largely on the exploitation of limestones which, because of their hardness and fossiliferous structure, could be cut and polished to produce an attractive 'marble-like' finish. True metamorphosed marbles, with few exceptions, if needed had to be imported from Europe and elsewhere and marble imports into Britain for decorative purposes date back as far as Roman times.

Thin section of Purbeck 'marble'

The only true metamorphosed limestone marbles quarried in Britain were worked in western Scotland in Tiree, Skye etc, some achieved short-lived commercial success such as the serpentinous green and white streaked variety from the Isle of Iona quarried from the Pre-Cambrian outcrops (Dimes 1990; Viner 1992). A recent revival is the variegated serpentinous marble from the Ledmore Quarries in Sutherland.

In the Pre-Cambrian Mona Complex of north west Anglesey the once famous Mona Marble ('leek' green to dark green and purple serpentinite) was quarried on a small commercial scale for decorative use (Hull 1872).

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