Aargau quarry supplies Switzerland’s last shell limestone

Switzerland’s only quarry still extracting shell limestone produces up to 15 tonnes a week in Hendschiken, in the canton of Aargau, SRF reports. The stone, known as Mägenwil shell limestone, is used for fountains, statues and building features, as well as for restoring historic structures.

The limestone is 18 to 20 million years old and formed from the remains of shells and other marine life deposited on the seabed. Although shell limestone occurs in many parts of Switzerland, only a few places have layers thick enough to be quarried.

The stone takes its name from Mägenwil, where it was once extracted. Work at the Hendschiken quarry began about 300 years ago, according to Emil Fischer AG co-owner and operations manager Roger Leuenberger. The company now has 25 employees.

Instead of using explosives, the quarry relies on drilling and sawing to avoid damaging the valuable blocks. The work includes the use of a large chain-saw-like cutting machine. The company recently received the Aargau Heritage Protection Award for its careful extraction methods and craftsmanship.

Leuenberger says the quarry can continue operating at the surface for about 70 more years. After that, extraction would have to move underground. Co-owner and workshop manager Leander Egger says the company has a responsibility to ensure there is enough stone to restore historic buildings made from it.

The limestone can be found in buildings including Muri Abbey, Lenzburg and Wildegg castles, the Swiss National Bank, the Federal Supreme Court and Zurich’s Grossmünster, which is currently being restored. The company also has four aspiring stonemasons, including Sina Maboudi Harehdasht, who says turning a square block into something artistic gives him a sense of fulfilment.