Sandstone is the most important rock type used to construct the buildings in Dalkeith Country Park, from the magnificent Dalkeith Palace to more mundane buildings such as the Stables.

Sandstones consist of grains of minerals, most commonly quartz, that have been packed together and then cemented by other minerals. Good quality sandstones with small grains cemented tightly together can be intricately carved, whereas poorer sandstones have larger grains with cements such as iron or calcite which sometimes don’t hold grains together firmly. By looking closely at local buildings you will be able to see variations in the nature of different sandstones.

The close-up photo of a section of a wall in Restoration Yard shows the yellow, orange and brown colouration which comes from iron-rich solutions which drained through the sediments after burial under further deposits of sand. Some of the stones show intensely folded beds, formed when the wet sand grains were stirred up by local movements in the earth’s crust.

Dalkeith Palace, St Mary’s Church and Montagu Bridge are likely to have been faced by Craigleith Sandstone extracted from one of several quarries at Granton, north of Edinburgh.

The Orangerie was designed by William Burn and built around 1832-4, possibly from Craigleith Sandstone which is 340 million years old. The building has twelve sides and twelve Roman Doric columns, with radial iron trusses to support the glazing. Designed to cultivate oranges, the combination of soot from the chimney which darkened the glass and the polluted local water supply meant that the experiment failed and the building was used to grow ferns instead.