BEIJING, April 30 -- China will levy a resource tax on rare earths, tungsten and molybdenum based on sales value instead of production quantity, the Ministry of Finance announced on Thursday.

The new tax, taking effect from May 1, is set at 6.5 percent for tungsten, and at 11 percent for molybdenum.

Resource taxes for light rare earths are set at 11.5 percent, 9.5 percent, and 7.5 percent, respectively in Inner Mongolia Autonomous Region, Sichuan Province, and Shandong Province, while for medium and heavy rare earths it is generally set at 27 percent.

The ministry also said last week that the resources will be exempt from export tariffs from May.

Rare earths, a class of 17 minerals, are some of the most sought after metals due to their military use and role in green technology like wind turbines and car batteries. China meets over 90 percent of world demand, but at the cost of much pollution.