Tunnels unveil hidden treasures

A 33cm calcite, now on show at the Natural History Museum in Sion Keystone

Rare crystals have been unearthed during construction of a new rail tunnel through the Lötschberg in canton Bern.

Scientists say the discoveries could help boost understanding of conditions in the Alps millions of years ago.

The tunnel is the second to be built through the Lötschberg in western Switzerland and forms part of a transalpine rail link between Germany and Italy.

Work on the tunnel has involved boring deep into the earth, which has allowed geologists and mineralogists to study and collect crystals which are normally inaccessible.

“Although only a relatively small amount of different mineral types have been found, the richness and variety of the crystals uncovered has been remarkable,” said geologist André Henzen.

Henzen says that four of the finds have been particularly spectacular. The haul includes two of the largest crystals of their kind ever uncovered in Switzerland – a 12.7 centimetre pyrrhotite (iron sulphide), and a 3.7cm fluorapophyllite (sillicate).

Also uncovered were two calcite crystals of a rare length and dimension, measuring around 30cm by 1cm. All are now on show at the Natural History Museum in Sion.

High hopes

Scientists are pinning their hopes of further discoveries at the Gotthard tunnel, another transalpine rail link in canton Uri in central Switzerland.

The tunnel, which will be 60 kilometres long, is set to become the longest rail tunnel in the world. It has so far thrown up 22 different types of mineral – from the common quartz to rare monazite.

There has even been the discovery of a previously unrecorded mineral, Amstegite, at the construction site in the village of Amsteg.

Scientists say the tunnel represents a unique opportunity to gather more information on the Alps. This is due to the depth of the digging, which is expected to reach an unprecedented 2,000 metres.

By studying minerals found at this level, experts hope to find out more about what the Alps were like millions of years ago.

The composition of the minerals, which remain unchanged at such depths, could give some clues as to whether a region was under water or dry land.

“It’s really an excellent scientific opportunity because it’s very rare to see such structures – veins of whitish quartz full of crystals – inside a rock,” said Marco Antognini, from the Cantonal Natural History Museum at Lugano.

High market value

But such rare crystals are also collector’s items and fetch high prices. Some sought-after stones have been valued at SFr10,000 ($8,178).

All finds technically belong to the canton, but it is inevitable that some find their way onto the black market, via the miners who find them.

For this reason, the cantons concerned have started offering rewards to workers who hand over their discoveries to geologists.

In this way the cantons hope to avoid a repetition of what has happened in canton Valais in western Switzerland.

Although the canton is rich in minerals, very few have ended up in its museums. The rest have either been sent abroad or have ended up in private collections.

swissinfo, Maddalena Guareschi, Lugano (translation: Isobel Leybold)

Key facts

Four exceptional minerals have been found in the Lötschberg area – two rarities and the two largest of their kind in Switzerland.
22 different types of mineral have been found during construction of the Gotthard tunnel so far.
Some minerals can fetch as much as SFr10,000.
The largest quartz ever found in Switzerland measured one metre and weighed 800 kilograms.