A challenge, a dream, an obsession : to show the public a block of eclogite weighing more 850 kg taken from the mountains above Zermatt, at a height of 3,500 m. The rock is made of pillow lava produced underwater at a depth of 2,500 m over the mid-ocean ridges of the sea which separated Europe from Africa 160 million years ago. It is unique in that it was buried 100 km under the earth before rising to the surface.