A raw 15-carat piece of johnstonotite 80-percent clear costs the equivalent of about $1,600 in Mozambique, but after processing, insetting and passing through a few hands the final price in a swish jewelry piece will be 10 times as much, Ge says.

The price of premium gems continues to rise, and that means his saddlebags are always swelling with cash as he makes his rounds; that and his foreign face make him a prime target for robbers.

Ge was born in Heilongjiang province in Northeast China, where winter lasts five months and temperatures often drop below minus 25 C.

For someone brought up in such unforgiving conditions and now leading life on the edge in a country more than 10,000 kilometers from home, you might expect the 51-year-old to have a fair degree of the rough and tumble about him, but the outward signs of that are hard to find, and he has a soft voice and wears a semi-permanent smile. However, he also possesses an acute sense of knowing when to move on.

In Heilongjiang after leaving school he worked as a technician for more than 10 years until his father became seriously ill, and he had to quit the job to take care of him.

In 1996 he got a chance to work as a technician for a big electronics company in South Korea on a two-year contract, but a strike at the factory left him jobless in a foreign country, and over the next eight years he took countless temporary jobs to make a living, including washing dishes in restaurants and bricklaying.

But while he was there, Ge met some Chinese who were in the gemstone trade. They barely spoke Korean, so Ge stepped in to help from time to time and gradually picked up basic knowledge about gemstones.

In 2004 he returned to China, which by then was barely recognizable to him, and opened a factory making the Korean condiment kimchi. However, it failed to take off. He finally opened a small shop selling gems in Beijing, but profits were slim, and after four years the business folded.