Cornish “Alps” and China Clay, Cornwall

Cornish “Alps” and China Clay, Cornwall

The Cornish Alps, St. Austell, Cornwall
The Cornish Alps, St. Austell, Cornwall

Cornish Alps??? As you drive across Cornwall, tall white mounds appear in the distance, visible for miles. These euphemistically named “mountains” are the debris of the China clay mining that has been the backbone of Cornwall’s economy for over 250 years. It is only after a visit to the Wheal Martyn China Clay Mine Museum near St. Austell, Cornwall that we understand what the mounds represent.

The Pit, Cornwall
The Pit, Cornwall

China clay is used in a variety of products like paper and pharmaceuticals, but it is perhaps best known as the source of China porcelain. A mixture of kaolin clay and a variety of other materials, including bone ash (used to make “bone” China) fired at high temperatures to produce a delicate, shiny ceramic, porcelain was first produced by the Chinese thousands of years ago. Marco Polo introduced it to the West when he brought some back to Europe dubbing it “Porcellana” in Italian, the word used for the cowry shell which he thought it resembled. In those days porcelain was as much a symbol of wealth as gold and silver.

Although the French and Germans managed to produce hard paste porcelain using minerals discovered on continental Europe, it was the discovery of high-grade kaolin in Cornwall by pharmacist/apothecary William Cookworthy in 1746 that started England on the path to porcelain production.

Unfortunately, in the process of mining kaolin, the land, effectively, is destroyed. What was once granite moorland inhabited by grazing cattle and a few farms is now dotted with enormous, deep gashes in the earth where nothing lives. At least a dozen of these are scattered around the area near St Austell, Cornwall. The process displayed in the museum continues to this day although technology has significantly modernized it without, unfortunately, finding a less destructive method of extraction.

The turquoise water in the pit
The turquoise water in the pit

The first step in mining kaolin is blasting the ground to reach the clay, in the process, progressively creating  deep and vast pits, hundreds of feet in size. The extra earth and rocks are removed and heaped in high mounds, known locally as the “Cornish Alps.” According to information at the Museum, for every ton of china clay extracted, nine tons of mineral waste products are created and dumped onto the Alps. To give you an idea of the scope, since production started in Cornwall, 120 million tons of china clay have been extracted and, according to some sources, there are reserves for another 100 years. Imagine what over a billion tons of waste looks like.

Once the cliff face is exposed, powerful jets of water are blasted against it to loosen the kaolin and dissolve it. The resulting liquid created by this hydraulic extraction runs down the slope and fills the pit below with a milky turquoise, “slurry” solution. Using power (originally provided by water wheels and steam) the water is pumped out of the pit into channels where the sand settles on the bottom. The remaining china clay particles and mica enter a series of wooden trenches where the mica drops out. From there, the clay flows into ponds to settle over a period of several days while the surface water progressively is siphoned off.

Once the clay has reached the consistency of heavy cream, it passes through pipes to another area where, in the past, coal furnaces dried it out. A ton of coal was required to dry 10 tons of clay. You can image how much coal was burned before alternative power sources were developed.

The Wheal Martyn Museum, Cornwall
The Wheal Martyn Museum, Cornwall

Before it was allowed to set, the wet clay was put into blocks, making it easier to break into pieces for loading and shipping. As a final step, women were employed to brush debris off the bottom and sides of the dried clay blocks before they were loaded for transfer to ships waiting in the Charlestown harbor. Before the advent of the railroad, heavy wagons pulled by horses trudged through the alleys of St Austell to reach Charlestown where the clay was loaded on ships through chutes for transportation around the world.

Mining has been a tradition in Cornwall for centuries and Cornish miners are renowned worldwide. Generations of families earned their livelihood through the extraction, processing, and transportation of  china clay; legends and songs have developed around it. While it has been a way of life for centuries, as with everything else, there is a downside. The mining of the kaolin has significantly impacted the environment. Some mines still operate, others sit, inactive, their deep pits nothing more than sterile gashes across the land. The Wheal Martyn Museum has preserved the history of mining while turning the area around the mine into a nature park and educational center. However, only one pit has been reclaimed by a group of environmentalists and concerned citizens who have turned the earth into a vibrant, living garden and environmental research/education center — the Eden Project. But that is another story!

IF YOU GO
The Wheal Martyn China Clay Country Park and Museum (Carthew, St. Austell, Cornwall, PL26 8XG; tel 44-0172-685-0362; www.wheal-martyn.com) Open Tuesday to Monday 1000 to 1600 til 1700 in the summer. To get to the museum follow the B3274 north of St Austell and look for brown signs starting at the Stenalees roundabout.

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