“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, a frenetic marketplace dominated by prospectors trying to unload their catch on savvy wholesalers — or hapless tourists who often return home with overpriced rocks.

Hu Xianli, a self-professed jade fanatic from eastern Zhejiang Province, said he had been duped countless times over the years. At best, he has grossly overpaid for mediocre specimens. At worst, he has mistaken chemically treated rocks for mutton-fat beauties.

A retired railway engineer, he likened his relationship with jade to an overpriced college education. “In the early years I paid a lot of tuition, but now that I’ve finally graduated, I’m not so easily fooled,” said Mr. Hu, 59, as a throng of overeager sellers, hands full of egg-size stones, thrust their wares into his face.

Although archaeologists have unearthed Neolithic jade tools along the Yellow River, the Chinese affection for the stone received a lift around 1600 B.C., when Shang dynasty royals took to sleeping on jade pillows, signing edicts with jade chops and interring their loved ones in jade-tile frocks. Legend suggests that only emperors were allowed to possess carved jade and that the pursuit of an especially cherished specimen might be worth the deaths of 10,000 soldiers. It is no coincidence that the Chinese character for king has the same root as the character for jade.

Contemporary Chinese is flecked with references to jade — the word is used to describe beautiful and pure women — and many people say they believe it has medicinal and even magical powers. A chip of jade worn around the wrist can soothe a frightened child, improve circulation or absorb bad energy, the Chinese say. According to an age-old belief, jade provides a link between the physical and spiritual worlds.