Next year a 175-tonne Brazilian quartzite sculpture will take its place at a site on America`s West Coast. Conceived by the internationally renowned sculptor known simply as Eino, the work features a 5m diameter globe symbolizing the work of the late David Ross Brower, an American environmentalist.

Called \'Spaceship Earth\' by its Finnish-American creator, the sculpture uses 88 sections of the stone to form the sphere.

Weighing two tonnes apiece, the hard, Azul do Mar sections had to be precision ground to produce the required curve. They were then drilled to accept the stainless steel pins that will link them together.

There will also be 1,426 small pieces of cast bronze attached to the surface of the globe to represent the continents. These, too, require small diameter drilling for fixing pins.

Nimbus TW3 thin wall diamond core drills are being used to core out every hole. The fixing of the small bronze pieces requires 5,000 x 8mm diameter holes. When it is installed, a further 300 x 14mm diameter holes will be needed to accept the pins that will hold the stone sections together. More holes are needed up to 50mm diameter.

Eino says: "This particular blue quartzite is ideal for my purpose because of its colour, resistance to discoloration and its ability to remain stable under all conditions - including earthquakes. However, at 6.5 on the Mohs scale it is extremely hard and difficult to work, so the use of diamond tools is mandatory."

The cutting, shaping and drilling of the raw stone took place over eight months at the Cachoeiro de Itapamirim plant of Gramil, the producers of the stone. Eino set up a ten-man team of Gramil workers and trained them specially for the project.

Eino praised the diamond tools from Nimbus that he said had enabled the work to be completed ahead of schedule.