Donghai county in Lianyungang, in East China's Jiangsu province, is widely recognized as "China's county of crystal". It is where you can get high-quality natural crystal products.

Rich in mineral resources, the county has about 37 kinds of minerals, including rock crystal, quartz and rutile. It has a total of 300 million metric tons of quartz and a reserve of 300,000 metric tons of crystal. Its crystal reserve accounts for half of the country's total.

"Not only do we have the largest quantity of crystal but also the best quality," says Chen Lin, the president of the Donghai Crystal Research Association.

"The crystal in Donghai has the highest purity. More than 99.99 percent of its content is silicon."

"The output and sales value of the crystal sector there constitutes half of that of the whole country, which makes the county the largest crystal market in China."

The crystal from Donghai is famous in China, and has been praised by many men of letters.

Su Dongpo, a poet in the Song Dynasty (960-1279), mentions the county nine times and its crystal four times in his work.

The crystal coffin of the late chairman Mao Zedong was made of 32.2 tons of crystal from the county.

In recent years, the county's crystal industry has developed rapidly. And it aims to be the world's top crystal center in the years to come.

The crystal from Donghai has both industrial and civil uses, including jewelry and artifacts, according to Chen.

In 1991, the first Donghai Crystal Festival was held in the county. And since then, the 10-day festival, has been celebrated around October every other year.

In 2013, the county produced more than 250 million pieces of crystal jewelry and crystal artifacts, with a value of around 7 billion yuan ($1.02 billion).

As of 2018, the county has more than 3,000 crystal processing factories, producing about 30 million pieces of crystal jewelry and more than 5 million crystal artifacts.

The Chinese Crystal Arts and Crafts Mall, located in the county, now also sells to overseas markets. It imports more than 1,000 metric tons of raw crystal from Brazil, South Africa, Madagascar and Russia, every year and exports the processed products to more than 30 countries and regions.

The annual value of the mall's output is now around 100 million yuan ($14.6 million), making the crystal industry one of the most important sectors in Donghai.

Liu Maomao contributed to this story.