Phone Payw, who was a professor at the University of Yangon in the former capital of Myanmar, moved to Ruili in 1990 with only 80,000 kyats (then equal to about 7,000 yuan) to his name. But he was confident that the jade industry would soon go through a boom. He started with a small piece of cloth on which he laid some bracelets. Now, 23 years later, he owns three stores on the street.

About half of the more than 60,000 Myanmar traders in Yunnan sell jade and gems, Phone Payw says. "You know, my friends in Myanmar can live a good life if they earn 50 yuan a day. And if a man earns 2,000 yuan a month in Myanmar, he will probably marry a very beautiful girl."

Many Myanmar businessmen in Ruili just visit regularly, renewing their entry and exit papers each year. "They have made huge fortunes in this province as our country has superb stones," he says.

Each year, Myanmar exports about 15,000 metric tons of jade stones and 60 percent are bought by the Chinese - on the Chinese mainland and in Hong Kong, Taiwan and Singapore. More than 60 percent of jade pieces bought on the mainland are imported through customs in Ruili, he says.

Earlier this year, the Myanmar central government altered its policy and will only allow the export of manufactured jade products in the future. The new policy has attracted the attention of jade traders over the border in Yunnan, who think it will affect supply, which could then raise the price, Ke Wencong says.

The price of jade reached a record high three years ago, but amid the economic slowdown in China, Myanmar jade is no longer selling that well, even though it maintains a good price in the market, Ke says.

"We want the price to go up steadily, not surge up. In that way, we could make profits with less risk," says He. "The new policy might further drive up the price, but it's still uncertain and most traders are waiting to see what happens."

Li Yingqing and Guo Anfei contributed to the story.