Producers step up research to tackle technical problems

For someone wearing a $8,000 diamond ring, color, clarity, cut and carat are what make the gem stone valuable.

But for some labs that grow diamonds in China, these are not the most important properties. Instead, high electrical resistivity, heat conductivity and hardness are what count. At least, these are what potential clients such as Chinese semiconductor companies are banking on.

China's leading lab-grown diamond makers, whose combined production takes up about 90 percent of the world's total, are stepping up research efforts by cooperating with research institutions to develop lab-grown diamonds as semiconductor materials, experts said.