After complaints from Minnesota's Cambria Co., the U.S. Department of Commerce has ruled that Chinese firms illegally dumped underpriced quartz products into the United States. As a result, additional tariffs will be levied.

Similar to the complaints from the U.S. steel industry — including from companies on the Iron Range — Cambria argued that China was heavily subsidizing quartz exports, allowing companies an unfair advantage over U.S. competitors.

Cambria, based in Le Sueur, first petitioned the Commerce Department and the International Trade Commission to intervene in April. Investigations started in May, and various preliminary rulings have been made since, including several this month.

As the largest U.S. producer of quartz countertops, backsplashes and floor tiles, Cambria led the effort to document and report the dumping, said Marty Davis, the company's president and CEO. Other companies' complaints were filed under seal.

The complaints were an effort to "protect free trade," as well as the jobs of his 2,000 employees, he said.

China not only subsidized its exports, allowing the products to be sold below cost, but also instituted a 40 percent tariff on quartz imports to the country, Davis said.

In 2017, China exported quartz valued at $459.6 million into the United States, the government said. Cambria estimates that the amount increased to $526 million for the first nine months of this year, up from $5 million in 2010.

In its complaint, Cambria said Chinese products were so discounted they displaced $1.2 billion worth of U.S. quartz purchases last year.

"Commerce's recent announcement is an important step toward restoring a level playing field in our industry," Davis said.

Last week, the department said "certain quartz surface products from the People's Republic of China are being, or are likely to be, sold in the United States at less than fair value."

In September, the Commerce Department increased tariffs on select Chinese quartz imports more than fivefold. After finding more violations, the United States earlier this month increased the tariffs even more.

While it previously established hefty tariffs against Fasa Industrial Corp. Ltd., Foshan Hero Stone Co. and Foshan Yixin Stone, it will now increase those duties and expand its list of violators. The expanded list includes CQ International Ltd. and Guangzhou Hercules Quartz Stone Products Co.

Other Chinese quartz exporters will face similar tariffs "based entirely on adverse facts available," the Commerce Department said.

In a Nov. 20 notice, Commerce agreed that the China importers were largely selling goods at prices that were below cost and invited other U.S. producers to file comments.