BEIJING - A large diamond deposit that can be mined for more than 30 years has been discovered in Liaoning province, officials from the local geology and mineral resources exploration bureau said on Wednesday.

The deposit, in Wafangdian, Northeast China's Liaoning province, contains an estimated 200 kilograms of diamonds and is the largest such discovery during the past three decades in the province, said Yu Wenli, director of the bureau of geology and mineral resources exploration in Liaoning.

The diamond mine, with little impurity, has a high grade and its value could be up to several billion yuan (hundreds of millions of dollars), according to Yang Zhanxing, deputy director of the bureau.

"Our exploration work is still going on and we plan to finish it within three years," Yang said. "This area probably has more diamond deposits and the amount may increase in the future."

In 2010, the bureau also explored a diamond reserve in Wafangdian and the latest discovery is less than 50 km from the old deposit, Yang said.

But he added the bureau has no exact plan to exploit the new deposit at present.

Zhang Hongtao, chief engineer from the Ministry of Land and Resources, was happy to hear the news of the diamond discovery.

"China actually has few diamond resources. The biggest diamond mine of the country is in the Wafangdian area and it is also the only place where rocks can become jewels after processing," Zhang said.

Besides Wafangdian, Shandong province also has some diamond resources, but the quality of most rocks there is low, he said.

However, the ministry has not made a professional and official evaluation of the new diamond deposit, which is a must for qualifying minerals, he said.

Diamond resources are mainly found in South Africa, India and Siberia, "but there have been no finds of diamond deposits on such a large scale around the world in the past decade," he said.

Nearly 90,000 netizens have started a discussion on micro blogs about going to Liaoning to dig for their fortune during the Spring Festival.

However, Yang broke those micro-bloggers' "diamond dream", telling them that diamonds are a national resource that cannot be exploited by individuals.

Diamond expert Zhang Tianzuo said this discovery will not affect the price of diamonds across the country in the short term.