WELSH granite is being used to entertain millions in one of the most popular sports in the Winter Olympics.

The rock from Trefor, North Wales, is being made into stones for curling because the supply from its traditional source in Scotland has run short.

For many years the blue hone, found only on Ailsa Craig in the Firth of Clyde in Scotland, has been used to make the curling stones.

But the quarry has run out so the Welsh rock must now also be used for the stones, which weigh 42 pounds each.

Curling is played by pushing the rock down the ice. A twist of the handle on the rock can make it curl as it makes its way to the other end.

Players try to make their rock land as close as possible to the tee, a small circle at the other end - so the qualities of the granite are very important to players.

But many are asking for how long it will be possible to obtain this indispensable raw material.

Experiments are already under way on a vein discovered in a quarry in western Canada. It is an Indian granite that contains many of the much appreciated qualities of blue hone and the Welsh Trefor, according to mining experts.

However, players who have tried out the stones on the rink do not agree.

There is also news from Alpine, an American firm from Wisconsin which specialises in material for curling. It is offering stones made of china and ceramics.

It would certainly mean a reduction in costs for a complete set of stones. Already in 2001 in Winnipeg, Canada, federal trainers tested it.

Those who were present said the results were good. But tradition dies hard and many trainers from the World Curling Federation were not really convinced and refused to make any official comment in its favour.

In the meantime Trefor stone continues to be used in the popular winter sport - more than six million people tuned into the previous Winter Olympics to watch Britain's women's curling team win gold.

Rhona Martin's team beat hot favourites Canada in the semi-finals and then squeezed past Switzerland in the final to clinch Britain's first Winter Olympics gold medal for 18 years at Salt Lake City in 2002.

Today the women face Sweden while the men take on Canada in a bid to recapture that glory.

But the game is only really played in Scotland where the curling population is approximately 25,000 strong.

In Wales there are about 100 curlers, on Deeside in North Wales.