Building stones of the Highlands and Islands

Reflecting the richly varied geology of the Highlands and Islands, many different sedimentary, igneous and metamorphic rock types have been exploited for building purposes. Intermittently over a period of 5000 years, stone has formed the principal building material in the region. This talk will focus on the sources and properties of stone used for load-bearing masonry and roofing in pre-1919 buildings but will also consider stone resources for new build, conservation and repair purposes. From the Industrial Revolution the region became a major producer and exporter of granite, slate, flagstone, and sandstone with much stone being transported by sea. Today granite and metamorphic rocks are primarily worked as sources of aggregate. Slate has not been quarried since the 1950s. Flagstone and sandstone production continues at several quarries. In 2016 it was estimated by BGS that of 17 quarries in Scotland producing building stone, only 7 were continuously active. Before the days of rail and road transport, local sourcing of building stone was the norm, as testified by evidence of hundreds of small quarries. However, as elsewhere in Britain, the building stone industry declined rapidly from the early twentieth century, to be displaced by brick and concrete production for most construction with stone relegated to its present use as ‘geological wallpaper’.