The opening ceremony of the 2017 China (Changle) International Gem Fair is held on Oct 13 in Changle County of Weifang, East China's Shandong province. [Photo by Han Beibei/ Sdchina.com]

Jointly organized by the circulation industry promotion center of the Ministry of Commerce, the Gems and Jewelry Trade Association of China, the Shandong Provincial Department of Commerce and the Weifang government, the four-day event attracted more than 300 exhibitors from 20 countries and regions including the US, Russia, South Korea, Italy, Thailand and Sri Lanka.

Visitors appreciate valuable gemstones exhibited at the 2017 China (Changle) International Gem Fair in Weifang, Shandong province. [Photo by Han Beibei/ Sdchina.com]

Various activities were also carried out during this year's event, including tourism promotions, business invitations, a high-end sapphire exhibition, a photographic exhibition featuring gold jewelry and a Chinese painting and calligraphy exhibition.

Changle, one of the world's major sapphire production areas, has been dubbed as the "Gem City of China". It is one of the few places in the world with rich sapphire reserves. Its sapphire is characterized by large size, intactness and purity of color. There are also some significant features that distinguish it from those of other producing areas in the world, such as Thailand and Sri Lanka.

The 2017 China (Changle) International Gem Fair includes three themed exhibition sections and 200 booths, attracting huge crowds to visit. [Photo by Han Beibei/ Sdchina.com]

To improve the fame of its sapphires, the county has held a string of promotions across the world in recent years and remarkable economic results have been achieved. More than 2,000 companies in the county are involved in sapphire manufacturing, processing and trading, and according to official data currently produce a total of 13 million carats annually, bringing in 36 billion yuan ($5.45 billion).