The Zhengzhou Sino-Crystal Diamond company is planning to invest $98.3 million (637 million yuan) in a diamond factory with a production capacity of 1.02 billion carats per year, the stcn.com news website reports.

Construction of the factory is estimated to take two years. The plant is expected to pay for itself in 4.6 years and once operational is predicted to generate sales revenue of $76.5 million and net profit of $22.3 million annually.

According to a report by the company, which did not say where the factory is to be built, China's domestic demand for diamonds will reach 20 billion carats by 2013, and 60% of that demand will be for stones of high quality.