|BGS image ID: P528116|
The shale oil industry started in Scotland in the 1850s reaching a peak in 1912 when 12,000 people worked in the industry. With the onset of the First World War and the importation of cheap oil from British interests in the Persian Gulf the industry saw rapid decline.
The image shows the steps from raw oil-shale fresh from the mine to a finished product - a packet of candles made from paraffin wax. The samples were sourced from the Pumpherston Oil Company Limited at Mid-Calder, a leading manufacturer in the Scottish shale oil industry.
Raw, black oil-shale (top left) was crushed and heated in a retort with injected steam to produce crude oil, this undergoes the first distillation to produce crude distillate (green oil). Top right, the spent oil shale. A second distillation of the green oil produced heavy oil containing paraffin. This was then separated into blue oil and crude solid paraffin. The latter paraffin wax in its unfinished state was refined and then manufactured into candles.
A full set of samples from each step in the process and the final products are held in the BGS collections in Edinburgh.