Diamonds are this nation's best friend

These small folded squares of pink or white paper are so thin and light that you would think there would be nothing inside them. However, once you open them you see the unmistakable sparkle of bright diamonds.

Chu laughed when he saw my surprised face. "You are a little disappointed to see such treasure wrapped so roughly? You're holding $100,000," he smiled.

According to the AWDC, the industry-established foundation, each year about 130 million carats of diamonds are mined worldwide. Of those, 84 percent of all rough diamonds and 50 percent of all polished diamonds pass through Antwerp. Diamonds represent 5 percent of total Belgian exports and 15 percent of all Belgian exports outside the European Union, making diamonds the nation's most important export product worldwide.

Among the non-European markets, the largest destination for diamonds is China, which has become the new driving force of the old city of Antwerp.

Wang Tingting (left) was hired by Dayekh Diamond to deal with Chinese customers. Fu Jing / China Daily

"In the beginning, I got no recognition at the bourse," Chu says. "Every day now, they greet me with 'Hi, young Chinese man, you're here.'"

According to the AWDC, the annual total value of global rough diamonds is nearly $9 billion. They are set in jewelry that is valued at nearly $50 billion.

It also says that global supply is expected to decline, falling behind expected demand growth that will be driven by China, India and the United States. "Over the next 10 years, supply and demand are expected to grow at a compound annual rate of 2 percent and 5.1 percent."

China's rising middle class has changed Antwerp and the diamond industry over the past decade.

In China, most customers don't realize that almost every diamond on their jewelry passed through the city.

About two years ago, China became the biggest destination for polished diamond exports from Antwerp, overtaking the US, says Ari Epstein, head of the AWDC. The center's research report says China will account for an estimated 29 percent of the global rough-diamond market's growth through to 2023, as its middle class expands and the rural population moves into the cities.

"Current projections suggest that the middle class will almost triple in size by 2023, and rough-diamond demand will more than double to about $5 billion in that year in China," Epstein says.

Middle-class households currently make up only 19 percent of China's population, but most forecasts say that percentage will rise to 44 percent by 2023.

"Diamond demand could accelerate if middle-class affluence grows faster," Epstein says. "With more spending power at their disposal, some will likely buy more expensive diamond pieces."