From a muddy riverbed, the stones that are more valuable than gold

AS LONG as anyone can remember, the muddy river that flows through the oasis city of Khotan in China's mainly Muslim province of Xinjiang has yielded creamy white stones, their rough edges polished smooth by the waters that tumble down the mountains from Tibet.

And as long as anyone can remember, those stones - a type of semi-translucent jade - were about as valued as, well, a pile of river rocks.

But these days, Khotan is mad about jade, or at least the riches it has brought to a city whose last bout of prosperity occurred a few thousand years ago, when traders from ancient Rome and Constantinople were making their way toward Xi'an, then the capital of the Chinese empire at the end of the Silk Road.

Ounce for ounce, the finest jade has become more valuable than gold, with the most prized nuggets of "mutton fat" jade - so-named for its marbled white consistency - fetching $3,000 (1,900) an ounce, a tenfold increase from a decade ago.

The jade boom, which appears to have reached a frenzy in the past year or two, has been fuelled by the ethnic Han Chinese, whose new wealth and a 5,000-year affinity for the stone has turned Khotan cotton farmers into jade tycoons.

"The love of jade is in our blood, and now that people have money, everyone wants a piece around their neck or in their home," Zhang Xiankuo, a Chinese salesman, said as he opened a safe to show off his company's most expensive carved items, among them a pair of kissing swans that retails for 95,000 and a contemporary rendition of a Tang dynasty beauty that can be purchased for50,000.

In a region convulsed by ethnic strife, it is notable that the manna appears to have enriched both Khotan's native Uighurs, Turkic-speaking adherents of Islam, and the more recently arrived Han Chinese, who are often viewed as colonisers.

"Jade has no meaning for our culture, but we are thankful to Allah that the Chinese go crazy for it," said Yacen Ahmat, a Uighur who spends seven days a week working the crowds at Khotan's jade bazaar.

One reason behind the spike in Khotan jade prices is that the jade is becoming increasingly scarce. Over the past decade, bulldozers and excavators have torn apart the banks of the White Jade River several times over.

Even if river jade is increasingly hard to find, the promise of instant riches brings entire families to the river.

Sceptics, however, say the rising prices have more to do with hype than scarcity. Wang Chunyun, a jade expert at the Guangzhou Institute of Geochemistry, says a thick lode of unexploited white jade runs through the Kunlun Mountains that skirt Xinjiang and Tibet.It can also be found across the world, from Australia to Korea to Poland.